UNIVERSITY  OF  CALIFORNIA 
AT   LOS  ANGELES 


GIFT  OF 


18 


THE  MOTORMAN 
AND  HIS  DUTIES 


A  Handbook  of  the  Theory  and  Practice  of 

Electric  Railway  Car  Operation 


By 

LUDWIG  GUTMANN 
Consulting  Electrical  Engineer 


Sixth  Edition  Revised  and  Enlarged 

By 

LAWRENCE  E.  GOULD 
Editor  Electric  Railway  Review 


CHICAGO 
THE  WILSON  COMPANY 

1907 


COPYRIGHT  1898 
BY  WINDSOR  &  KENFIELD  PUBLISHING  Co. 

COPYRIGHT  1903 
BY  WINDSOR  &  KENFIELD  PUBLISHING  Co. 

COPYRIGHT  1907 
BY  THE  WILSON  COMPANY 


TF 
965" 


PREFACE. 


The  purpose  of  this  book  is  to  familiarize  the 
reader  with  the  operation  of  an  electric  car.  It  will 
be  found  to  explain  in.  simple  language,  devoid  of 

io          mathematics  and  technicalities,  many  points  not  gen- 

*  erally  understood  by  the  average  employe  who  has  to 
do  with  the  operation  or  care  of  electric  railway  roll- 
ing stock.  Such  a  knowledge  cannot  fail  to  make  his 

2  services  more  valuable  to  his  company  and  more  sat- 
isfactory to  himself,  and  it  will  also  better  fit  him 

^          for  promotion. 

_£.  This   book   is   intended   not   only   to   explain   the 

parts  of  an  electric  motor  car,  but  to  give  some  gen- 

9  eral  instruction  and  advice  to  those  who  desire  to 
make  the  handling  of  cars  their  livelihood.  It  is  based 

.£  on  experience  gathered  during  a  number  of  years  in 
the  electric  railway  field,  instructing  motormen  in 

~$~        their  duties  and  work,  and  on  results  and  observation 

.*-          made  while  operating  roads      To  explain  some  elec- 

M  trical  effects  it  has  been  necessary  to  adopt  a  few 
comparisons,  which,  though  not  exactly  correct  from 
a  scientific  standpoint,  give  the  reader  a  clear  picture 
of  what  is  meant. 

The  author  desires  to  acknowledge  the  generous 
assistance  of  the  manufacturing  companies  whose  ap- 
paratus is  explained  and  illustrated  in  the  following 
pages. 


238541 


CONTENTS. 


Chapter  I.  PAGE 

A  GLANCE  OVER  THE  ROAD  -------  1 

Chapter  II. 

PRINCIPLES  OF  THE  ELECTRIC  MOTOR         -----      10 

Chapter  III. 
GENERATING  AND  DISTRIBUTING  POWER  -  23 

Chapter  IV. 
OVERHEAD  CIRCUIT  AND  THIRD  RAIL 39 

Chapter  V. 
THE  ELECTRIC  RAILWAY  MOTOR 52 

Chapter  VI. 
CAR  WIRING  AND  PARTS  --------74 

Chapter  VII. 
CONTROLLERS  ----------  92 

Chapter  VIII. 
MULTIPLE-UNIT  CONTROL  --------  116 

Chapter  IX. 
OPERATION  OF  CONTROLLERS  -------  129 

Chapter  X. 
BRAKES  AND  THEIR  OPERATION  ------  140 

Chapter  XI. 
How  TO  REMEDY  TROUBLES 175 

GLOSSARY 187 


CHAPTER  I. 


A    GLANCE    OVER    THE    ROAD. 

One  who  will  read  and  study  as  well  as  gain  by 
his  practical  experience  will  be  worth  to  his  employer 
much  more  than  is  the  average  employe  of  today. 
Therefore,  he  should  be  able  to  secure  a  position  more 
readily.  It  is  evident  that  the  more  one  knows  about 
his  vocation  the  better  compensation  he  can  expect. 
A  man  may  start  "on  the  platform"  and  by  faithful 
service  and  study  he  may  advance  to  be  a  car  inspector, 
line  inspector  and  eventually  electrician  of  the  road. 

Anyone  wishing  to  qualify  himself  for  car  serv- 
ice can  advance  in  two  ways— by  experience  in  operat- 
ing a  car  and  by  studying  the  theory  of  the  eiectrical 
equipment.  For  rapid  advancement  the  practical  work 
should  be  accompanied  by  electrical  reading. 

The  reader  who  desires  to  become  proficient  and 
know  more  than  just  simply  enough  to  run  his  car 
over  the  road  should  be  of  a  practical  and  mechanical 
turn  of  mind.  He  should  know  something  about  the 
use  of  tools  and  machinery.  To  become  familiar  with 
the  electric  car  equipment  the  best  plan  is  to  work  at 
first  in  the  barns  and  repair  shops.  One  will  there 


2  THE  MOTORMAN. 

learn  the  practical  side.  He  will  have  to  mount  motors 
on  trucks  or  repair  defective  pieces  of  machinery,  and 
by  frequently  handling  them  he  will  soon  familiarize 
himself  with  their  names  and  uses.  However,  not 
everyone  can  have  such  preparation  for  a  position,  and 
for  this  reason  we  will  do  the  next  best  thing,  namely, 
take  an  imaginary  trip  first  over  the  road  and  then 


Figure  1 — Interurban   Right  of  Way. 

through  the  car  shops,  mentioning  briefly  the  various 
parts  of  the  whole  system  and  the  devices  that  are 
necessary  to  operate  it.  Such  of  these  devices  as  come 
under  the  control  and  care  of  the  motorman  and  con- 
ductor will  be  described  in  detail  later  on  and  the 
principles  by  which  they  operate  will  be  explained. 


A    GLANCE    OVER    THE    ROAD.  3 

Essential  Parts  of  an  Electric  Railway. — To  begin 
with,  every  road  has  its  right  of  way;  the  cars  of  the 
city  roads  operate  over  tracks  laid  in  streets,  while 
those  of  interurban  roads  (Figure  1)  run  over  tracks 
built  on  a  private  right  of  way  located  across  the 
country  without  regard  to  public  roads.  By  cutting 
down  the  hills  and  filling  in  the  low  places  it  is  pos- 
sible to  build  a  track  in  the  country  over  which  the 
cars  can  operate  at  much  higher  speeds  than  in  cities 
where  the  grades  and  curves  of  the  rails  must  fit  those 
in  the  streets.  It  is  also  much  more  difficult  to  operate 
cars  through  the  crowded  streets  of  a  city  or  town 
than  it  is  on  a  fenced  right  of  wray. 

Nearly  everyone  is  familiar  with  the  track  and 
roadway  of  a  steam  railroad,  and,  as  the  better  inter- 
urban  electric  railways  are  built  with  tracks  as  near 
as  possible  like  steam  roads,  this  subject  need  not  be 
thoroughly  discussed  here.  The  tracks  of  city  roads, 
however,  are  very  different  from  those  of  steam  rail- 
roads. The  latest  kinds  of  track  for  street  railways 
have  a  very  substantial  foundation  of  concrete  on 
which  the  track  rails  rest,  as  shown  in  Figure  2.  In 
some  cities  ties  are  used  and  in  others  the  rails  are 
sunk  into  stringers  of  concrete  and  held  to  the  stand- 
ard gauge  of  4  feet  S1/^  inches  by  iron  tie-rods. 

The  electric  current  for  use  in  operating  the  cars 
as  they  move  along  the  track  is  generated  in  the  power 
house  and  carried  to  the  cars  through  a  trolley  wire 
or  third  rail,  which,  in  fact,  are  no  different  as  regards 
the  movement  of  the  car,  except  that  the  trolley  wire  is 
hung  above  the  middle  of  the  track  and  is  usually  of 
copper,  while  the  third  rail  is  supported  alongside  of 
the  track. 

It  should  be  understood  that  the  electric  current 


4  THE  MOTORMAN. 

in  the  wires  may  be  serving  to  transmit  hundreds  of 
horsepower  of  energy  and  yet  the  wire  look  "dead." 
It  is  necessary  to  be  cautious  about  coming  in  contact 
with  electric  wires  and  nothing  should  be  touched  that 
may  be  connected  in  any  way  with  the  circuit;  other- 
wise, a  severe  shock  will  be  received. 

Electric  Cars.— Probably  the  most  important  part 
of  an  electric  railway  from  the  motorman's  standpoint 


Transverse  Section 


Longitudinal  Section   ' 
Figure  2 — Track  Construction  In  City  Street. 

is  the  car.  Cars  are  of  two  kinds  with  respect  to  their 
operation — motor  cars  or  trailers.  The  motor  cars 
have  complete  equipments  of  electric  apparatus  so 
that  they  can  take  power  from  the  trolley  wire  and  be 
propelled  along  the  track  under  the  control  of  a  motor- 
man  on  the  front  platform.  The  trailer  cars  do  not 
have  this  electrical  equipment,  but  are  hauled  by  motor 
cars,  thus  requiring  the  services  of  a  conductor  only 
to  collect  the  fares. 


A    GLANCE    OVER   THE    ROAD.  5 

So-called  open  cars  consist  of  a  floor  structure 
usually  with  cross  seats,  a  roof  and  a  foot-board  or 
step  all  along  the  side  of  the  car.  To  protect  the  pas- 
sengers in  rainy  weather  open  cars  are  provided  with 
curtains  which  may  be  drawn  down  between  the  posts 
which  support  the  roof.  Closed  cars  (Figure  3)  have 
sides  up  to  about  the  tops  of  the  seats  and  windows 
fitted  in  between  the  roof  posts  and  this  siding.  Plat- 
forms are  usually  provided  for  both  ends  of  closed 


Figure  3 — Single-Truck  City  Car. 

cars  and  passengers  must  step  onto  these  platforms 
first  before  getting  inside  the  car. 

Both  open  and  closed  cars  are  used  for  city  service, 
but  for  interurban  service  the  closed  car  body  only  is 
used  (Figure  4). 

A  motor  car  is  composed  of  the  following  essen- 
tial parts: 

1.  A  car  body  for  carrying  the  passengers. 

2.  Trucks  and  wheels  for  supporting  the  motors 
and  the  car  body. 

3.  Motors  for  propelling  the  car. 


THE  MOTORMAN. 


4.  A     device     for 
collecting    the     cur- 
rent from    the   wire 
or  third  rail. 

5.  Controllers     for 
feeding   and   regula- 
ting the  current  used 
by  the  motors. 

6.  Brakes  for  stop- 
ping the  car. 

7.  Devices  for  pro- 
tecting the  electrical 
apparatus. 

Figures  5,  6,  7 
show  different  con- 
structions of  car 
trucks,  but  these  are 
only  a  few  of  the 
types  which  are  in 
general  use.  Figure. 
5  shows  a  type  of 
-running  gear  used 
on  short  cars  of 
from  25  to  30  feet 
in  length.  Strictly 
speaking  this  is  not 
a  truck,  but  two 
pairs  of  wheels,  each 
pair  and  its  axle 
being  connected  with 
the  car  through 
springs.  Figures  6 
and  7  show  bogie 
trucks  which  are 


A    GLANCE    OVER    THE    ROAD.  7 

used  with  long  cars,  two  such  trucks  being  used  under 
each  car.  The  essential  parts  of  car  trucks  are  two 
sets  of  wheels  mounted  on  axles  which  are  held  in  posi- 
tion by  bearings.  The  bearings  are  fixed  to  side  frames 


which  give  the  truck  its  rigidity.     Springs  are  placed 
between  the  bearings  and  the  parts. 

The  brake  rigging  is  also  a  very  important  part, 
on  which  the  car  body  rests  in  order  to  prevent  too 
severe  jarring  of  the  car  body.  In  the  case  of  the 


Figure  6 — Maximum  Traction  Truck  for  City  Car. 

"single  truck''  the  lower  sills  of  the  car  are  bolted 
directly  to  the  side  frames  of  the  truck,  but  where 
double  trucks  are  used  a  piece  known  as  the  truck 
bolster  extends  between  the  two  side  frames  and  is 
pivoted  at  its  center  to  the  car-body  bolster. 


THE  MOTORMAN. 


A    GLANCE    OVER    THE    ROAD. 


The  '  brake  rigging, 
which  will  be  described 
in  detail  in  a  later  chap- 
ter, is  also  a  very  impor- 
tant part  of  the  equip- 
ment of  the  truck,  and  on 
most  modern  electric  cars 
both  hand  and  power 
brakes  are  used.  The 
hand-brakes  are  operated 
by  manual  force,  but  the 
air-brakes  utilize  the 
power  from  the  trolley 
wire,  as  will  be  explained 
in  a  later  chapter. 

Figure  3  shows  a  car 
mounted  upon  a  single 
truck,  this  being  a  type 
of  equipment  suitable  for 
operation  on  city  lines. 
Figure  4  shows  a  double- 
truck  car  built  for  use 
on  a  western  high-speed 
interurban  railway.  Fig- 
ure 8  is  a  floor  plan  of  a 
large  city  car  arranged  in 
such  a  way  that  loading 
and  unloading  is  very 
rapid.  The  location  of 
the  different  parts  and  fit- 
tings is  shown  and  an  idea 
of  the  relative  dimensions 
given. 


CHAPTER  II. 


THE    PRINCIPLE    OF    THE    ELECTRIC    MOTOR. 

Many  persons  have  the  idea  that  a  dynamo  or  an 
electric  motor  is  so  complicated  a  device  that  it  takes 
years  of  study  to  understand  it.  Nothing  is  farther 
from  the  truth.  The  fact  is  that  it  is  built  on  one  of 
the  simplest  principles,  and  if  this  principle  is  well 
understood  it  will  be  easy  to  understand  any  machine, 
because  in  analyzing  we  always  go  back  to  the  simple 
principle  and  leave  out  the  many  complicated  addi- 
tions which  may  be  attached  to  a  machine  for  one 
reason  or  another. 

Principle  of  the  Magnet. — A  dynamo  or  motor 
frame  is  a  powerful  steel  magnet,  and  differs  in  prin- 
ciple but  slightly  from  the  common  horseshoe  magnet. 
Figure  9  represents  a  magnet 
which  one  can  buy  in  any  hard- 
ware store.  To  understand  the 
action  of  a  dynamo  or  motor,  it 
becomes  necessary  to  understand 

this  little  magnet.  It  is  a  piece  of  flat  steel  bent  into 
the  form  of  a  horseshoe,  which  is  hardened  and  after- 
ward magnetized.  It  has  been  found  that  steel,  when 
hardened,  will  retain  magnetism  for  a  long  time,  that 
is,  for  months  and  years;  provided,  that  it  constantly 


THE    PRINCIPLE    OF    THE    ELECTRIC    MOTOR.      11 

has  some  work  to  do.  For  this  reason  the  keeper  B  is 
always  found  with  the  magnet.  The  keeper  or  arma- 
ture B  is  a  simple  piece  of  soft  iron  which,  when 
brought  near  to  the  end  of  the  magnet  poles  or  the 
horseshoe,  is  attracted  and  held  by  the  magnet.  If  we 
attempt  to  remove  this  piece  of  iron  B  from  magnet  A 
we  find  that  it  requires  some  force  —  that  it  takes 
energy  to  pull  off  the  iron  piece  from  the  magnet.  We 
therefore  are  confronted  by  the  fact  that  this  bent 
piece  of  steel  has  energy  stored  in  it,  and  that  this 
energy  is  capable  of  doing  work.  The  magnet,  which 
at  first  had  to  be  charged,  takes  up  energy  which  is 
stored  in  it,  and  which  afterward  it  can  return  to  do 


Figure  10.  Figure  11. 

useful  work.  It  is  similar  to  a  spiral  spring.  We 
have  to  spend  energy  to  compress  it  (Figure  10),  but 
the  moment  we  reduce  the  pressure  we  feel  that  the 
spring  tries  to  utilize  the  stored  energy  and  force  our 
fingers  apart  (Figure  11). 

If  we.  remove  the  armature  from  the  horseshoe 
magnet,  the  energy  acts  from  one  end  of  the  magnet  to 
the  other  through  the  air.  The  energy  or  flow  of 
energy  is  not  visible  to  the  eye,  but  the  results  of  this 
force  are  made  visible  by  the  action  of  iron  filings 
when  brought  near  to  a  magnet.  With  the  aid  of  iron 
filings  it  is  found  that  this  force  is  very  intense  near 
and  between  the  ends  of  poles,  and  spread  in  curves 
the  farther  it  goes  out  into  the  space  surrounding  the 


12  THE    MOTORMAN. 

magnet  poles.  Figure  12  gives  a  clear  view  of  some 
of  these  lines.  The  spots  which  are  marked  N,  S,  are 
the  places  where  the  paper  would  touch  the  ends  or 
poles  of  the  magnet,  if  it  were  held  beneath  the  sheet 
of  paper  presenting  the  figure. 

The  iron  filings  which  are  thrown  on  top  of  the 
sheet  arrange  themselves  in  lines  as  seen.  Between 
the  poles  these  lines  appear  straight,  and  become  more 
and  more  curved  the  longer  the  path  becomes  from  one 
pole  to  the  other.  It  must,  however,  be  borne  in  mind 
that  the  sheet  is  but  a  single  plane  through  the  sphere 
or  globe  surrounding  the  magnet,  and  that  the  power 
of  activity  goes  in  all  directions  surrounding  the  poles, 
as  the  branches  and  leaves  surround  the  trunk  of  a 
tree.  These  same  curves 
of  activity  can  be  seen  to 
go  in  all  directions  in 
space  by  taking  a  small 
compass  needle  and  pass- 
ing it  from  one  pole  to  the 
other.  During  its  travel 

,,          .„  .  Figure  12. 

the  needle  will  change  its 

position  with  relation  to  the  two  poles,  and  will 
always  take  such  a  position  that  its  two  ends  lie 
in  line  with  the  particular  curve  which  unites  it  with  the 
two  poles  (Figure  13).  It  is  owing  to  this  custom  of  rep- 
resenting this  force  by  the  curved  lines  that  it  became 
usual  to  speak  of  " magnetic  lines  of  force,"  which, 
however,  should  not  be  considered  as  actual  lines,  nor 
that  they  simply  connect  the  two  poles,  but  as  a  force 
which  threads  through  the  whole  length  of  the  magnet, 
as  shown  in  Figure  14.  This  energy  is  vested  not  only 
in  the  extremities  of  poles,  but  is  the  sum  of  the  forces 
of  all  the  particles  of  steel  constituting  the  magnet. 


THE    PRINCIPLE    OF    THE    ELECTRIC    MOTOR.      13 

The  energy  is  in  the  magnet,  but  its  manifestations 
become  apparent  most  strongly  at  the  points  where  it 
passes  from  the  magnetic  medium  to  a  non-magnetic 
one.  Air  is  non-magnetic,  while  iron  and  steel  are 
strongly  magnetic  substances.  Owing  to  the  great 
preference  that  the  magnetism  has  for  iron,  it  selects 
the  path  indicated  in  Figure  14  rather  than  to  go 
straight  from  the  pole  N  to  the  S  pole  through  the  air. 
In  passing  through  the  iron  the  lines  of  magnetic  force 
cause  the  armature  or  keeper  also  to  become  a  magnet. 
The  poles  are  marked  N  and  S  as  abbreviations  for 
"North"  and  "South,"  because  they  correspond  to 
the  poles  or  ends  of  the  magnetic  needle  of  a  compass. 


Figure  13. 


Figure  14. 


The  keeper  becomes  a  magnet  under  the  influence  of 
the  horseshoe  magnet. 

If  we  substitute  for  the  keeper  a  permanent  mag- 
net, viz.,  a  -piece  of  steel  in  which  the  poles  are  fixed, 
we  find  that  if  the  two  magnets  are  faced  N  to  S  and 
S  to  N,  as  in  this  figure,  they  will  attract  each  other. 
If  placed  so  that  the  two  N  poles  are  together  and  the 
two  S  poles  are  together,  no  attraction  will  take  place, 
but,  on  the  contrary,  they  will  repel  each  other;  and 
from  this  fact  comes  the  rule  "like  poles  N,  N,  or  S,  S, 
repel  each  other:  unlike  poles  attract  each  other." 

Electro-Magnets.— A  great  step  in    advance    was 


14 


THE    MOTORMAN. 


made  when  the  following  fact  was  discovered:  It  was 
found  that  if  a  wire  carrying  an  electric  current  and 
a  magnetic  needle,  delicately  suspended,  were  brought 
close  to  each  other,  the  needle  was  deflected  to  one 
side.  If  the  current  flowed  in  a  wire  above  the  needle 
in  the  direction  from  south  to  north,  that  is,  if  the 
wire  itself  was  held  in  a  direction  due  north  and  south 
above  the  needle,  and  the  current  flowed  north  through 
the  wire,  then  the  north-seeking  end  of  the  needle  was 
deflected  to  the  west.  If  the  wire  was  held  above  the 
needle,  but  turned  round  so  that  the  current  flowed 


Figure  15. 


Figure  16. 


from  north  to  south,  then  the  north-seeking  point  of 
the  needle  was  deflected  to  the  east.  Lastly,  if  the  wire 
was  held  below  the  needle,  the  direction  of  the  deflec- 
tion was  reversed.  It  was  clear,  then,  what  long  had 
been  suspected,  that  there  was  some  connection  be- 
tween magnetism  and  electricity. 

This  experiment  also  showed  that  the  electric  cur- 
rent could  act  through  space,  and  acts  on  the  magnetic 
needle  just  as  the  horseshoe  magnet  did.  If  that  is 
the  case,  then  it  must  disturb  the  space  surrounding 
it  while  a  current  is  flowing;  it  must  establish  a  sphere 
around  itself  of  the  nature  of  a  magnet,  a  sphere  that 
has  magnetic  properties.  Investigating  the  space 


THE    PRINCIPLE    OF    THE    ELECTRIC    MOTOR.      15 

around  the  wire  with  iron  tilings,  we  find  a  grouping 
of  the  little  iron  particles  (Figures  15  and  16),  and  that 
the  wire  carrying  a  current  attracts  iron  filings.  Fig- 
ure 16  shows  a  picture  of  the  force  around  the  wire, 
while  Figure  15  shows  an  end  view  of  Figure  16. 

Figure  17  represents  a  magnetic  needle  surrounded 
by  a  coil  of  wire  carrying  a  current.  It  appears  that 
we  have  here  the  principle  of  an  electric  motor  with 
this  one  difference,  that  owing  to  the  arrangement  of 
parts  the  movement  is  not  rotary.  Motion  is  imparted, 
but  not  continuous  motion,  in  one  direction.  It  is 


Figure  17.  Figure  18. 

found  further  that  if  we  take  a  spool  of  wire  (Figure 
18)  without  any  iron  near  it  and  send  an  electric  cur- 
rent through  it,  as,  for  instance,  from  a  battery  B, 
through  the  coil  A,  it  behaves  just  as  a  magnet  does; 
viz.,  that  it  exhibits  a  north  pole  at  one  extremity 
and  a  south  pole  at  the  other,  and  that  it  attracts  one 
end  of  the  magnetic  needle  at  one  end  and  the  other 
at  the  opposite  end — just  what  we  know  will  take 
place  if  we  have  an  ordinary  straight  magnet  or  bar 
magnet  instead  of  the  spool  with  the  current  flowing 
through  it. 

Lastly,  one  more  phenomenon  must  be  mentioned, 
which  will  complete  our  picture.  If  we  take  a  spool  of 
wire  A  (Figure  19)  and  connect  it  to  another  coil"  B 


16  THE    MOTORMAN. 

several  feet  away,  which  is  close  to  a  magnetic  needle 
C,  and  we  move  a  magnet  D  toward  the  first  coil  A, 
then  the  needle  momentarily  is  deflected.  The  needle 
C  is  far  enough  away  not  to  be  under  the  directing  in- 
fluence of  the  magnet  D.  What  takes  place  is  this: 
The  sphere  surrounding  the  magnet  pole  in  its  ap- 
proach affects  the  coil  A,  and  this  disturbance  in  space 
is  the  cause  of  the  flow  of  an  electric  current  in  coil  A, 
which,  passing  through  the  coil  B,  disturbs  the  air  sur- 
rounding it  and  changes  it  into  a  magnet,  which  in 


Figure  19. 


Figure  20. 


turn  acts  on  the  compass  needle.     Here  we  have  one 
of  the  earliest  transmissions  of  power  to  a  distance. 

Principle  of  the  Dynamo. — Returning  now  to  our 
simple  magnet  (Figure  20),  it  will  be  clear  and  in  ac- 
cordance with  facts  that  if  a  loop  of  wire,  placed  be- 
tween the  poles  of  a  horseshoe  magnet  and  connected 
to  a  delicate  instrument  for  measuring  electric  cur- 
rents, is  turned  between  the  poles  of  this  magnet,  such 
turning  produces  a  temporary  current  which  affects  and 
deflects  the  needle  of  the  instrument.  An  electric  cur- 
rent is  generated  which  flows  from  the  loop  to  the  in- 
strument and  back  again,  with  the  effect  of  deflecting 
the  needle  of  the  instrument.  What  has  been  found 
is  that  taking  a  magnet  and  turning  a  coil  of  wire  in  its 
sphere  of  activity,  or  (as  it  is  called  technically)  in  its 


THE    PRINCIPLE    OF    THE    ELECTRIC    MOTOR.      17 

magnetic  field,  an  electric  current  is  created  or  gen- 
erated in  this  coil.  The  reader  will  now  see  that  if  this 
simple  magnet,  with  a  loop  or  a  coil  placed  between  its 
poles,  is  conveniently  arranged  on  a  shaft  so  as  to  turn 
it  continually  in  the  same  direction  (Figure  21),  a  cur- 
rent will  be  produced  that  will  last  for  some  time 
instead  of  being  simply  an  impulse;  this  constitutes 
a  dynamo  in  its  simplest  form.  Owing  to  its  primitive 
mechanical  arrangement,  and  also  owing  to  the  weak- 
ness of  the  permanent  magnet,  such  an  arrangement,  of 
course,  gives  but  very  weak  currents  and  is  not  a  corn- 


Figure  21.  Figure  22. 

mercial  device,  but  this  fundamental  idea  can  be  recog- 
nized in  any  and  all  of  our  modern  machines. 

The  Dynamo. — Now  let  us  start  once  more  with 
our  permanent  magnet  and  go  through  the  evolution 
until  we  reach  the  dynamo  of  today.  Figure  9  shows 
the  permanent  horseshoe  magnet  with  its  keeper  in 
place.  Figure  22  shows  the  keeper  or  armature,  as 
we  will  call  it  hereafter,  some  distance  from  the  poles, 
with  the  field  of  activity  in  the  space  between  the  poles 
and  the  armature.  The  armature,  under  the  influence 
of  the  magnet,  becomes  also  a  magnet  and  must  ex- 
hibit poles,  which  are  indicated  by  the  letters  N  S, 
N  S,  in  such  a  way  that  a  south  pole  of  the  armature 
will  stand  before  a  north  pole  of  the  magnet.  Under 
these  conditions  the  force  exerted  causes  mutual  at- 


18  THE    MOTORMAN. 

traction  between  the  magnet  and  its  armature,  result- 
ing in  a  motion  of  the  smaller  piece,  which  moves 
toward  the  magnet,  where  all  motion  stops  when  it 
rests  against  the  poles.  If  we  now  wind  a  coil  around 
the  armature,  we  will  obtain  a  temporary  current 
which  lasts  as  long  as  the  armature  is  approaching  the 
poles  (Figure  23),  but  as  soon  as  the  armature  comes 
to  rest  the  current  ceases.  In  a  dynamo  it  is  desired 
to  produce  currents  continually,  and  therefore  it  is 
necessary  to  modify  the  form  and  relationship  of  the 
armature  to  the  magnet.  This  is  shown  in  Figure  24. 
In  this  case  the  armature  is  mounted  on  a  spindle,  a 


Figure  23.  Figure  24. 

cylindrical  piece  of  iron,  which,  magnetically  consid- 
ered, is  a  bar,  as  in  Figure  22.  Figure  25  shows  a  mag- 
net like  Figure  24  with  the  wires  wound  around  the 
cylindrical  armature  core.  The  wires  and  the  shaft  are 
shown  in  section.  The  wire,  which  is  to  be  rotated  in 
the  space  of  magnetic  activity,  is  placed  as  near  the 
poles  as  possible,  as  shown  in  section  in  Figure  25. 
This  figure  is  obtained  by  placing  the  magnet  in  the 
plane  of  the  leaf  or  book  (Figure  26).  The  armature 
and  wires  lie  at  right  angles,  penetrating  through  all 
the  leaves.  If  the  armature  in  Figure  26  be  cut  off, 
the  end  that  projects  on  top  is  shown  in  Figure  25. 

The  Commutator. — To  use  the  currents  generated 
and  bring  them  to  devices,  such  as  lamps  or  motors, 
we  have  to  make  some  provision  for  collecting  the  elec- 


THE    PRINCIPLE    OF    THE    ELECTRIC    MOTOR.       19 

trie  current  from  the  rotating  armature  to  stationary 
points.  This  is  done  by  connecting  the  ends  of  the  ro- 
tating coils  to  metallic  contact  pieces  or  rings,  called 
a  commutator,  which  will  be  explained  later. 

Field  Magnets. — To  produce  strong  currents  strong 
magnets  are  needed.  It  was  found  that  permanent 
steel  magnets  were  weakened  when  an  armature  with 
winding  was  made  to  generate  heavy  electric  currents. 
It  also  was  found  that  soft  iron,  when  wound  with 
coils  through  which  a  current  was  sent,  became  a  far 
more  powerful  magnet  than  could  be  obtained  in  any 


Figure  25.  Figure  26. 


other  way.  Therefore  it  became  the  practice  to  use 
wrought  iron,  cast  iron  or  soft  steel  magnets  for  dyna- 
mos, and  to  magnetize  them  by  a  winding  through 
which  an  electric  current  is  sent  as  long  as  the  ma- 
chine is  working.  Figure  27  shows  our  simple  magnet 
provided  with  energizing  coils,  which,  to  distinguish 
them  from  the  windings  on  the  armature,  are  called  the 
field  magnet  windings,  or,  in  short,  the  field  windings, 
because  they  belong  to  that  magnet  which  establishes 
the  field  in  which  the  other  part  or  armature  is  to  ro- 
tate. Between  the  magnet  poles  is  the  armature  with 
a  winding  and  contact  device  or  commutator. 

If  we  now  compare  the  complete  dynamo  with  the 


20  THE    MOTORMAN. 

original  magnet,  we  find  that  the  only  difference  be- 
tween them  is  that  the  dynamo  is  made  more  powerful 
than  the  magnet  by  the  application  of  the  coils,  and 
the  differences  in  the  armatures  are  that  the  motion  is 
changed  from  a  lateral  to  a  rotary  one;  further,  that 
the  armature  is  provided  with  a  winding  and  a  device 
for  conveniently  taking  off  the  current  generated  by 
the  rotating  of  the  armature  m 

winding  in  the  sphere   of  en- 
ergy of  the  magnet.     It  there- 


Figure  27. 


Figure  28. 


fore  is  clearly  seen  that  there  is  no  frictional  con- 
tact required  between  the  armature  and  the  field 
magnet,  an  erroneous  view  so  frequently  expressed 
by  people  not  conversant  with  the  subject. 

We  are  now  prepared  to  look  critically  at  any  kind 
of  a  dynamo,  from  the  simplest  and  weakest  to  the 
largest  machines  built  today,  without  confusion  and 
without  the  idea  of  great  complication  as  regards  the 
nature  of  its  operation,  for  now  the  single  magnet  with 
the  single  loop  between  the  poles  will  be  ever  present 
before  the  mental  eye. 

Figure  28  shows  the  outline  of  an  Edison  dynamo, 
one  of  the  older  types.  The  horseshoe  magnet  with  its 
windings  will  readily  be  recognized  in  this  machine.  It 


THE    PRINCIPLE    OF    THE    ELECTRIC    MOTOR.      21 


is  built  with  its  poles  downward  and  its  armature  be- 
tween the  poles,  which  are  extended  so  as  to  surround 
the  armature.  Figure  29  shows  a  front  and  side  view 


Figure  29. 

of  the  armature,  the  iron  core  being  completely  cov- 
ered by  the  wire.  On  the  right  side  may  be  seen  the 
contact  terminals,  called  the  commutator,  which  is 
marked  A.  Figure  30  is  a  skeleton  of  a  multipolar 

(many  poles)  field  mag- 
net, which  shows  a 
magnet  with  four  poles 
and  consists  of  four 
horseshoe  magnets,  one 
of  which  is  shown 
shaded.  The  armature 
is  shown  located  be- 
tween the  poles.  This 
elementary  description, 
explaining  the  nature 
of  the  generation  of  an 
electric  current,  shows 

clearly  how  simple  is  the  principle  underlying  an  elec- 
tric machine.  It  is  a  magnet  at  rest  combined  with  a  ro- 
tating piece  of  iron  wrapped  with  wire,  that  constitutes 
a  dynamo ;  and  furthermore,  a  machine  that  is  used  as  a 


Figure  30. 


22  THE    MOTORMAN. 

dynamo  may  also  be  used  as  a  motor.  The  name  dy- 
namo or  motor  changes  with  the  service  to  be  rendered. 
If  the  machine  shown  in  Figure  28  be  driven  by  a  steam 
engine,  and  is  supplying  electric  current,  it  is  a  dy- 
namo; if,  however,  an  electric  current  is  applied  to 
it,  and  it  does  mechanical  work,  it  is  a  motor.  These 
differences  should  be  clear  in  the  mind  of  the  reader. 
If  there  are  parts  he  does  not  understand  clearly,  he 
should  discuss  the  subject  with  such  persons  of  his 
acquaintance  as  are  competent  to  explain  the  matter 
to  him. 


CHAPTER   III. 


GENERATING    AND    DISTRIBUTING    POWER. 

Now  that  we  have  obtained  a  general  idea  of  the 
fundamental  principles  of  the  electric  dynamo  and 
motor  we  can  next  more  readily  understand  the  power 


Figure  31 — A  Large  Power  Station. 

system  of  an  electric  railroad.  We  shall  make  a  men- 
tal inspection  of  the  power  generating  and  distributing 
apparatus,  beginning  with  the  coal  pile  in  the  boiler 


24  THE    MOTORMAX. 

room  and  ending  with  the  car  in  charge  of  the  motor- 
man.  In  a  subsequent  chapter  it  will  be  shown  how 
important  it  is  that  a  motorman  should  recognize  the 
value  of  power  and  therefore  learn  to  operate  his  car 
in  the  most  economical  way. 

The  Power  Station.— To  begin  with,  a  power  station 
usually  is  a  fireproof  building  in  which  are  housed  boil- 


Figure  32 — Boilers  and  Pumps. 

ers,  engines,  dynamos  and  electrical  switching  appa- 
ratus. Here  the  current  is  generated  and,  by  means 
of  wires  on  poles  along  the  track,  it  is  distributed  for 
use  in  propelling  the  cars.  The  machinery  in  some 
power  stations  is  operated  by  water  wheels,  but  the 
larger  number  of  power  plants  are  run  by  steam 
engines. 


GENERATING    AND    DISTRIBUTING    POWER.         25 

Boilers. — To  make  steam  for  running  the  engines 
which  drive  the  dynamos,  a  battery  of  boilers  is  neces- 
sary. These  boilers  comprise  two  types,  known  as 
"water  tube"  and  ''fire  tube."  The  fire-tube  boilers 
are  seldom  used  except  for  very  small  plants.  They 
are  called  fire-tube  boilers  because  the  burning  gases 
from  the  coal  on  the  grates  pass  through  a  number  of 
parallel  iron  tubes  around  which  is  the  water.  In  the 
water-tube  boilers  (Figure  33),  the  relative  spaces  oc- 


Figure  33— Sectional  View  of  Boiler. 

cupied  by  the  burning  gases  and  the  water  are  exactly 
the  opposite  to  fire-tube  boilers;  thus,  in  a  water-tube 
boiler  there  are  a  larger  number  of  tubes  containing 
water,  the  temperature  of  which  is  to  be  raised,  and 
between  which  the  hot  gases  are  passed;  the  ends  of 
these  tubes  filled  with  water  connect  with  cylindrical 
"drums"  in  such  a  way  that  when  the  water  in  some 
of  the  tubes  that  are  over  the  hottest  part  of  the  fire 
becomes  heated,  it  can  rise  into  one  of  the  drums  and 


26 


THE    MOTORMAN. 


GENERATING    AND    DISTRIBUTING    POWER.         27 

the  cooler  water  in  the  drum  pass  down  through  tubes 
in  the  hotter  part  of  the  fire,  and  thus  a  circulation 
take  place. 

The  water-tube  type  of  boiler  is  more  generally 
used  in  large  power  plants  because  of  its  economy  and 
safety. 

The  fuel  used  for  making  steam  in  boilers  usually 
is  coal,  although  some  power  plants  find  it  economical 
to  burn  crude  oil.  The  grates  on  which  the  coal  is 
burned  are  built  directly  under  the  front  of  the  tubes 
in  the  boiler,  and  coal  is  fed  onto  them  either  by  hand 
or  by  mechanical  stokers.  The  gases  from  the  burning 
coal  make  several  passes  between  the  rows  of  tubes 
and  then  leave  the  brick  setting  which  encloses  the 
firebox  and  boiler  and  connect  with  the  stack. 

Steam  Engines.— The  steam  is  taken  out  of  each 
one  of  the  boilers  and  fed  into  a  large  pipe  called  a  main 
header.  From  this  pipe  branches  lead  to  the  engine's 
cylinders.  Practically  everyone  is  familiar  with  the 
general  appearance  and  mechanical  operation  of  a 
steam  engine  having  as  its  essential  parts  a  cylinder 
within  which  a  closely  fitting  piston  is  moved  back  and 
forth  by  steam  pressure.  This  piston  transmits  the 
power  thus  generated  through  a  piston  rod  and  a  con- 
necting rod  to  a  crank  pin  on  the  engine  shaft.  Thus 
the  back-and-forth  motion  of  the  steam-driven  piston 
is  transformed  into  the  rotary  motion  of  the  engine 
shaft  revolving  in  its  bearings  (Figure  34). 

The  electric  generator  whose  elementary  principles 
we  have  already  discussed  is  usually  mounted  on  the 
same  foundation  with  the  engines,  so  that  the  revolv- 
ing part  of  the  generator,  called  the  armature,  can 
be  driven  directly  by  the  shaft  of  the  steam  engine. 


28 


THE    MOTORMAN. 


A  heavy  flywheel  of  large  diameter  is  also  driven 
on  the  same  shaft.  This  flywheel  is  for  the  purpose  of 
carrying  the  connecting  rod  over  the  dead-center  and 


Figure  35 — Turbine  Units  and   Condensers. 

making  the  engine  and  dvnamo  run  at  a  uniform  speed. 

Steam    Turbines.— The     steam     engine     and     its 

dynamo,  as  described,  occupy  a  large  floor  space  and 

therefore  require  a  comparatively  large  and  expensive 


GENERATING    AND    DISTRIBUTING    POWER.         29 

building  to  cover  them.  There  recently  has  been 
adopted  a  type  of  steam-driven  dynamo  which  occupies 
much  less  floor  space  and  is  thought  to  be  better 
suited  for  electric  railway  power  plants.  This  machine 
is  known  as  a  steam  turbine  unit,  several  of  which  are 
shown  in  Figure  35.  It  comprises  a  main  shaft  on 
which  are  mounted  a  large  number  of  blades  inclosed 
in  a  steel  casing  and  having  a  general  arrangement 
very  similar  to  a  turbine  waterwheel.  The  principle 


Figure  36 — Power   Station   Switchboard. 

on  which  the  turbine  operates  is  simple,  the  steam  in 
it  corresponding  to  the  water  in  a  waterwheel.  A  dy- 
namo is  mounted  on  the  same  framework  with  the  tur- 
bine, and  the  armature  is  built  on  the  same  shaft  that 
supports  the.  blades  in  the  turbine.  Steam  turbines 
are  known  as  horizontal  or  vertical,  depending  on 
whether  the  main  shaft  lies  in  a  horizontal  plane  or 
stands  vertically  on  its  end. 

"We  have  now  seen  how  the  coal  is  burned  under 
the  boilers,  which  generate  steam  and  drive,  by  means 
of  engines  or  turbines,  the  dynamos  which  develop  the 
electric  current  that  is  to  be  used  in  propelling  our 


30  THE    MOTORMAN. 

cars.  If  there  are  a  number  of  such  generating  sets  in 
the  power  station  the  current  from  each  dynamo  is 
brought  by  means  of  cables  to  a  switchboard  (Figure 
36)  where  there  are  electrical  meters  for  measuring 
the  quantity  and  quality  of  the  current,  and  where 
there  are  also  switches  for  combining  the  current  gen- 
erated in  each  dynamo,  so  that  the  total  output  of  the 
plant  may  be  fed  out  of  the  building  and  along  a 
transmission  line  to  supply  the  cars. 

Units  for  Measuring-  Electricity. — To  transmit 
electricity  from  one  place  to  another  a  certain  amount 
of  energy  has  to  be  spent  in  the  transmission  which  is 
thereafter  not  available  for  useful  work.  This  loss  of 
energy  is  due  to  the  resistance  of  the  conductor  which 
carries  the  current,  and  will  be  readily  understood  by 
its  similarity  to  water  flowing  through  a  pipe.  If  we 
transmit  a  volume  of  water  to  a  distance  through  a 
pipe  under  a  certain  pressure,  the  pressure  of  the  water 
at  the  further  end  of  the  pipe  will  be  considerably  less 
than  the  pressure  at  the  point  where  the  water  enters 
the  pipe.  This  loss  of  pressure  is  due  to  the  friction  of 
the  water  against  the  walls  of  the  pipe,  and  it  will  be 
readily  seen  is  greater  the  greater  the  length  of  the 
pipe,  and  will  be  less  for  a  given  volume  of  water  as 
the  size  of  the  pipe  is  larger.  And  the  same  way  with 
an  electric  current :  the  longer  the  conducting  wire  the 
greater  will  be  the  resistance,  while  by  increasing  the 
diameter  of  the  wire  the  resistance  will  be  reduced. 
The  smaller  the  amount  of  loss  in  the  transmitting 
lines  the  more  economical  is  the  working  of  the  system. 

We  have  spoken  of  the  volume,  pressure  and  re- 
sistance of  water  in  a  pipe  as  being  analagous  to  vol- 
ume, pressure  and  resistance  of  current  flowing 
through  a  conductor.  The  electrical  unit  of  quantity 


GENERATING    AND    DISTRIBUTING    POWER.         31 

corresponding  to  the  volume  of  water  is  called  the 
ampere.  The  electrical  unit  of  pressure  is  called  the 
volt,  and  the  unit  of  electrical  resistance  is  the  ohm. 
According  to  Ohm's  law,  the  current  in  amperes 
equals  the  pressure  in  volts  divided  by  the  resistance 
in  ohms.  This  law  is  generally  expressed  by  the 
equation : 

C  =  E-^R 

in  which  C  =  current  in  amperes 

E  =  electromotive  force  in  volts 
R  =  resistance  in  ohms. 

Methods  of  Distribution. — In  general  there  are 
three  methods  of  supplying  current  to  the  cars.  These 
are  here  stated  and  will  be  described  in  detail  later  on : 

1.  The  simplest  plan  is  to  feed  all  the  current  into 
the  trolley  wire  and  an  auxiliary  wire  or  feeder  cable 
supported  on  the  poles  which  hold  up  the  trolley  wire. 

2.  The  "alternating  current"  system    has    prac- 
tically the  same  general  arrangement  as  System  No.  1, 
but  differs  in  that  it  uses  the  so-called  alternating  cur- 
rent.   This  current  is  generated  in  the  same  way  as 
that  which   we   already  have   discussed,   except   that 
there  is  a  difference  in  the  method  of  making  connec- 
tions between  the  armature  coils  and  the  brushes.    We 
have  learned  that  on  the  end  of  the  commutator  shaft 
there  are  placed  a  number  of  copper  bars  to  connect 
with  stationary  brushes  which,  by  the  nature  of  the 
method  of  connections  and  the  rotating  of  the  arma- 
ture, unite  the  many  small  currents  passing  in  different 
directions  through  the  armature  into  a  large  current 
passing  to  the  outside  wires  in  only    one    direction. 
With  the  alternating  current  the  method  of  connection 
at    the    commutator    end    of    the    armature    is    even 


32  THE    MOTORMAN. 

simpler.  In  place  of  the  many  bars  there  are  only 
two,  bent  in  the  form  of  rings,  over  which  the  brushes 
slip ;  thus  the  currents  passing  in  opposite  directions 
through  the  various  armature  coils  are  not  fed  to  the 
line  as  current  all  moving  in  one  direction,  but  are 
sent  out  in  opposite  directions  as  the  different  coils  in 
the  armature  pass  by  the  north  and  south  poles  of  the 
generator.  The  fact  that  such  current  does  not  flow 
steadily  through  a  circuit  in  one  direction,  but  flows 
first  one  way  and  then  the  other  in  this  circuit,  brings 
about  the  name  "alternating"  by  which  this  current  is 
known. 

,3.  The  method  for  economically  feeding  long 
lines  comprises  the  use  of  what  are  known  as  alternat- 
ing-current generators,  the  current  from  which  can  be 
raised  in  pressure  and  fed  at  a  small  loss  over  a  long 
distance,  say  50  to  100  miles,  and  then  reduced  in  pres- 
sure ;  and  by  means  of  a  combination  of  an  alternating- 
current  motor  and  a  direct-current  generator,  the  prin- 
ciple of  which  we  already  have  considered,  it  may 
again  be  converted  into  suitable  current  for  use  in 
the  cars  and  motors  which  we  have  mentioned. 

The  Direct-Current  System.— The  electrical  trans- 
mission from  a  railway  power  station,  according  to  Sys- 
tem No.  1,  is  shown  in  diagram  in  Figure  37.  To  the 
left  will  be  noticed  the  dynamo,  which  is  connected  by 
means  of  a  commutator  brush  to  the  trolley  wire  (all 
switches,  circuit-breakers,  safety  devices,  etc.,  at  the 
station  and  on  the  car  have  been  omitted  for  the  sake 
of  clearness  and  simplicity).  Each  electric  car  is  indi- 
cated by  one  motor,  wheel,  trolley  and  controller.  By 
following  the  arrows  it  will  be  observed  that  the  elec- 
tric current  starts  from  the  dynamo,  goes  to  the  trolley 
wire,  from  there  to  the  trolley  wheels  and  to  the  con- 


GENERATING    AND    DISTRIBUTING    POWER.         33 

trollers ;  from  the  controllers  to  the  motors,  the  wind- 
ings of  which  are  indicated  by  a  few  turns,  and  from 
there  to  the  iron  body  of  the  motor,  to  the  car  wheel 
and  to  the  rail.  Through  the  rails  and  return  feed- 
ers it  flows  back  to  the  station,  where  the  second  brush 
of  the  dynamo  is  connected  to  the  rail.  This  completes 
a  circuit,  through  the  dynamo,  out  over  the  trolley 
wire,  down  through  the  motor  and  back  through  the 


n 


Figure  37 — Path  of  Current  for  Direct  Feeding. 

rails,  and  current  flows  over  this  circuit  whenever  a 
controller  is  put  in  operation. 

Principle  of  the  Transformer. — Before  describing 
the  other  two  systems  it  is  thought  best  to  describe  the 
transformer,  which  is  an  important  piece  of  apparatus 
used  in  both  the  alternating-current  and  direct-cur- 
rent systems  of  distribution. 

Alternating  current  has  some  properties  that  are 
not  possessed  by  direct  current,  the  most  interesting 
one  to  us  being  that  it  can  be  raised  in  pressure  with- 
oirt  the  use  of  a  generator.  The  medium  which  is  used 


THE    MOTORMAX. 


to  raise  the  pressure  of  alternating  current  is  known 
as  a  transformer.  (See  Figure  38.) 

A  transformer  consists  of  a  large  body  of  iron, 
around  which  are  wound  two  coils  of  wire.  "When  an 
alternating  current  is  fed  through  one  of  these  coils, 
following  the  principles  already  mentioned,  we  see  that 
lines  of  force  are 
set  up  in  the  iron 
around  which  this 
coil  is  wound.  We 
have  also  seen  that 
if  the  lines  of  force 
pass  through  a  mass 
of  iron  about  which 
there  is  a  coil  of 
wire,  a  current  will 
be  set  up  in  this 
wire;  therefore, 
when  an  alternating 
current  is  fed  into 
one  of  the  coils  of 
a  transformer  an- 
other current  is  in- 
duced in  a  second 
coil.  It  should  be 

noted  that  the  pressure  of  the  current  thus  generated 
is  greater  or  less  than  that  of  the  current  passing 
through  the  first  coil,  according  to  whether  the  num- 
ber of  turns  in  the  second  coil  is  greater  or  less  than 
the  number  of  turns  in  the  first  coil.  Transformers 
usually  are  built  with  a  definite  ratio  between  the 
number  of  turns  in  the  two  coils,  so  that  if  current  is 
fed  in  at  a  certain  pressure  it  is  known  beforehand 
at  what  pressure  it  will  be  taken  out  of  the  second 


Figure  38 — Section  of  Transformer. 


GENERATING    AND    DISTRIBUTING    POWER.         35 

coil.  Thus  it  is  seen  that  if  there  are  alternating-cur- 
rent generators  at  the  power  station  the  current  from 
these  may  be  fed  into  a  set  of  transformers  and  its 
pressure  raised  to  a  comparatively  high  voltage — say, 
40,000  volts. 

The  Alternating-Current  System. — Experience  has 
shown  that  current  can  be  transmitted  over  long  dis- 
tances with  a  comparatively  small  loss,  if  high  voltages 
are  used,  and  therefore,  in  System  No.  2  (Figure  39), 
the  general  circuits  include  transformers  for  raising 
the  voltage  at  the  power  station,  a  set  of  wires  known  as 
a  transmission  line  for  carrying  the  current  to  distant 
points,  and  other  transformers  connected  with  the  ends 
of  this  transmission  line  which  reduce  the  pressure  so 
that  it  can  be  fed  to  the  trolley  wire  at  a  voltage  low 
enough  to  be  used  safely  on  the  cars. 

It  should  be  noted  that  in  this  alternating-current 
system,  commonly  known  as  the  single-phase  system, 
there  is  no  direct-current  machinery.  The  types  of 
motors  used  under  the  cars  are  so  designed  that  they 
will  operate  on  either  direct  or  alternating  current,  and 
so  far  as  the  speed  and  propelling  power  are  concerned 
very  little  difference  will  be  noted  in  the  movement 
of  a  car  over  lines  supplied  by  these  two  methods  of 
distribution. 

Alternating-Current-Direct-Current  System. —  The 
method  of  distribution  indicated  as  System  No.  3  (see 
Figure  40),  is  a  combination  of  the  other  two  systems 
of  distribution.  It  comprises  alternating-current  trans- 
mission lines  as  in  No.  2,  and  direct-current  trolley  lines 
as  in  No.  1.  The  different  parts  of  the  system  are  as 
follows :  Alternating  current  is  generated  and  by 
means  of  transformers  in  the  power  station  its  pressure 
is  raised  to  an  economical  point  for  use  on  the  trans- 


36 


THE    MOTORMAN. 


GENERATING    AND    DISTRIBUTING    POWER.         37 

mission  line.  This  transmission  line  running  along  the 
trolley  poles  feeds  a  number  of  substations  which,  on 
the  interurban  lines,  are  located  about  10  miles  apart. 
Each  of  these  substations  includes  in  its  equipment  a 
set  of  transformers  which  reduces  the  transmission 
pressure  so  that  the  current  can  be  fed  into  an  alter- 
nating-current motor  located  in  the  substation  build- 
ing. This  motor  is  directly  connected  to  a  direct-cur- 
rent generator  which  generates  current  suitable  for 
operating  the  cars,  usually  at  600  volts  pressure.  By 
means  of  feeder  cables  the  current  from  the  direct- 
eurrent  generator  is  fed  to  the  trolley  and  then  to  the 
cars.  It  passes  through  the  motors  and  into  tae 
track  rails,  whence  it  returns  to  the  negative  side  of 
the  generator  in  the  substations. 

For  the  sake  of  simplicity  and  economy  in 
construction,  the  armatures  of  the  motor  and  the  gen- 
erator, which  are  used  to  convert  the  current,  are 
sometimes  wound  on  the  same  core  and  used  in  a  single 
set  of  field  magnets.  When  so  combined  the  machine 
is  known  as  a  rotary  converter  (Figure  41).  It  differs 
little  in  principle  or  method  of  operation  from  the 
motor-generator  set  first  mentioned  in  connection  with 
substation  apparatus.  This  system  of  transmission  is 
known  as  the  alternating-current-direct-current  method 
of  distribution,  and  is  probably  the  most  generally 
used  at  the  present  time. 

To  assure  clearness  it  probably  will  be  best 
to  again  state  the  three  general  methods  of  furnishing 
power  to  cars.  The  first  mentioned,  the  direct-current 
system,  uses  only  that  kind  of  current  which  flows  con- 
tinuously in  one  direction.  This  system  was  the  first 
to  be  used  for  propelling  electric  cars,  and  is  by  far  at 
the  present  time  the  most  generally  used. 

238541 


38 


THE    MOTORMAX. 


The  second  system,  known  as  the  alternating-cur- 
rent system,  employs  only  current  which  alternates  in 
the  wire.  Car  motors  for  this  type  of  distribution 
recently  have  been  developed  and  many  improvements 
made  in  their  control  apparatus,  so  that  for  long  lines 
in  the  construction  of  which  economy  of  transmission 


Figure  41 — A   Rotary   Converter. 

is  an  important  factor,  this  alternating-current  system 
is  fast  growing  in  favor. 

As  earlier  stated  the  third  method  comprises  the 
combination  of  the  other  two,  using  alternating-current 
machinery  for  generation  and  transmission  and  direct- 
current  apparatus  for  the  propulsion  of  the  cars. 
At  the  present  time  practically  all  of  our  large  city 
systems  and  a  great  majority  of  the  interurban  lines 
have  their  cars  operated  by  this  method. 


CHAPTER  IV. 


OVERHEAD    CIRCUIT    AND    THIRD    RAIL. 

In  transmitting  electric  power  certain  precautions 
arc  necessary.  The  electric  current  has  to  be  guided 
by  means  of  a  conductor,  which  in  practice  is  generally 
copper  wire,  and,  in  order  that  the  energy  transmitted 
shall  be  wasted  as  little  as  possible,  the  conducting  wire 
must  be  thoroughly  insulated  from  the  earth  and  from 
all  other  conducting  bodies.  It  was  found  at  an  early 
day  that  there  is  a  great  deal  of  difference  in  the  con- 
ductivity of  different  substances.  Some  conduct  the 
current  very  easily,  others  less  easily,  and  again  others 
do  not  conduct  the  current  at  all  unless  it  is  forced 
through  them  under  very  high  pressure.  The  first  class 
of  substances,  which  are  known  as  good  electrical  con- 
ductors, includes  all  metals,  and  of  the  metals  the  best 
conductors  are-  silver  and  copper.  The  last  class  of 
materials,  which  do  not  conduct  electric  current,  are 
called  non-conductors  or  insulators,  and  if  a  conductor 
is  attached  or  supported  upon  a  non-conducting  sub- 
stance, the  conductor  is  said  to  be  insulated.  Thus,  if 
we  should  lay  bare  electric  wires  in  the  ground  we 
would  receive  but  little  current  at  the  far  end,  because 
the  earth  is  itself  a  conductor  of  electricity  and  would 


40 


THE    MOTORMAN. 


return  a  greater  part  of  the  current  to  the  dynamo.  It 
is  evident,  therefore,  that  the  conductor  must  be  in- 
sulated from  the  earth  and  from  all  other  conductors  in 
order  to  transmit  the  current  to  a  distant  point  where 
it  is  desired  to  use  it. 

Insulators.— Perfectly  dry  air  is  one  of  the  best 
insulators  known,  while  water  containing  dissolved 
salts  and  other  impurities,  as  generally  found,  is  an 


STRAIN  INSULATOR 


SECTION   IXSCLATOR 


IIAXGEK  rrilVE    1'ULL-OVEH 

Figure  42 — Overhead   Fittings. 

excellent  conductor.  There  is  little  chance  for  cur- 
rent to  escape  from  a  wire  supported  on  insulating  ma- 
terial unless  moisture,  acids  or  dirt  are  to  be  found  on 
the  surface  of  the  insulators,  in  which  case  a  slight 
leakage  through  the  dirt  or  moisture  will  occur.  The 
best  and  most  commonly  used  insulating  substances 
are  porcelain,  glass,  mica,  rubber,  dry  wood,  silk,  shel- 
lac, paper  and  cotton. 

The  electric  current  has  to  be  produced  in  most 
by  operating  a  dynamo  by  means   of  a  steam 


OVERHEAD    CIRCUIT    AND    THIRD    RAIL.  41 

engine,  and  this  engine  receives  its  energy  from  the 
boiler  under  which  coal  is  burned.  The  energy  located 
in  the  coal  is  utilized  to  evaporate  the  water  in  the 
boiler,  and  the  steam  so  produced  actuates  the  engine, 
which  in  turn  operates  the  dynamo.  The  greater  the 
waste  in  electricity,  the  greater  will  be  the  coal  con- 
sumption. Therefore,  the  desire  to  avoid  losses  as 
much  as  possible,  such  as  leakage  on  electric  lines  or 
faults  or  leakage  on  devices  connected  therewith,  since 
they  form  part  of  the  circuit  the  moment  the  current  is 
allowed  to  pass  into  them.  For  this  reason  motors, 
controllers  and  other  parts  attached  to  the  car  are 


Figure  43— Sectional  View  of  Strain   Insulator. 

carefully  insulated,  and  the  overhead  conductor  is  held 
in  position  by  insulators  of  hard  rubber,  glass,  porce- 
lain, compounds  of  mica,  or  other  substances  put  into 
suitable  shape  under  great  pressure. 

Some  such  insulators  as  used  on  electric  railways 
are  shown  in  Figure  42.  In  most  cases  they  consist  of 
two  metallic  parts  which  are  separated  from  each 
other  by  a  strong  arid  thick  layer  of  insulation.  One 
metallic  part  is  then  connected  to  the  conductor  which 
is  to  carry  the  electric  current,  while  the  other  is  at- 
tached to  a  pole,  or  span  wire.  This  latter  may  be 
regarded  as  connected  to  the  earth,  but  the  other  end  is 
insulated  from  such  contact  by  the  interposed  layer  of 


42  THE    MOTORMAN. 

non-conducting  material.     Figure  43   shows  such  an 
insulator  in  section  disclosing  its  construction. 

The  circuits  of  most  electric  railways  include  the 
high-tension  transmission  line  of  alternating-current 
feed  wires  and  the  well-known  trolley  wire,  such  as  are 
shown  in  Figure  44.  Besides  the  trolley  wire  method 
of  carrying  current  to  the  cars,  there  are  the  third-rail 


Figure  44— Trolley  and  High-Tension  Wires. 

system  and  the  conduit  system.     This  third-rail  sys- 
tem has  been  mentioned  before. 

Third-Rail  System. — The  third-rail  system  is  one 
in  which  a  rail  called  the  third  rail  is  substituted  for 
the  overhead  trolley.  The  third  rail  may  be  placed 
either  between  the  two  track  rails  or  outside  of  them. 
The  third-rail  system  is  at  the  present  time  assuming 
considerable  importance  in  the  direct-current  electric 
railway  field,  and  this  type  of  construction  is  adopted 
where  heavy  cars  are  made  up  into  trains  and  operated 


OVERHEAD    CIRCUIT    AND    THIRD    RAIL. 


43 


at  high  speed.  The  reason  that  the  third-rail  system 
is  preferable  to  the  overhead  trolley  in  such  cases 
is  that  the  weight  and  speed  of  trains  requires  an 
amount  of  current  which  is  too  great  to  be  collected 
by  the  overhead  trolley  wheels,  owing  to  their  very 
limited  contact.  In  the  third-rail  system  the  sliding 
contact  is  maintained  by  means  of  a  shoe  which  slides 
along  the  top  or  bottom  of  the  third  rail,  and  may  be 


Figure  45 — Bracket  for  Under-Running  Third  Rail. 

given  sufficient  area  to  carry  any  required  amount  of 
current. 

The  first  commercial  installation  of  the  third-rail 
system  was  on  the  intra-mural  railway  at  the  World's 
Fair  in  1893.'  It  was  next  adopted  by  the  elevated 
roads  of  Chicago  and  afterwards  on  a  branch  line  of 
the  New  York  &  New  Haven  railroad.  The  system 
was  subsequently  extended  to  various  branches  of  the 
same  road.  It  was  next  used  on  the  Albany  &  Hudson 
Ry.,  after  which  it  was  installed  on  the  Aurora,  Elgin 
&  Chicago  "Ry.  There  have  since  been  built  a  large 
number  of  such  systems.  The  third  rail,  as  shown  in 


44  THE    MOTORMAN. 

Figure  45,  is  elevated  about  three  inches  above  the 
level  of  the  track  rails,  and  is  supported  on  insulators 
resting  on  the  ties.  In  this  country  the  third  rail  is 
always  located  outside  of  the  track  rails.  In  the  earlier 
third-rail  systems,  insulators  were  made  of  wood,  but 
it  has  been  found  that  after  a  year  or  two  of  service 
the  wood  absorbs  sufficient  moisture  to  partly  short- 
circuit  the  insulator,  and  cause  considerable  loss 
through  leakage. 

Aside  from  the  location  of  the  supply  conductor, 
there  is  no  difference  between  the  third-rail  and  the 
overhead  system,  so  far  as  the  circuits  upon  the  car 
are  concerned. 

The  third-rail  system  is  applicable  only  to  roads 
running  upon  a  private  right  of  way,  and  is  especially 
adapted  to  the  operations  of  cars  in  trains,  which  re- 
quires a  larger  amount  of  current  than  can  be  collected 
by  one  trolley  wheel.  Shoes  are  placed  at  the  journal 
boxes  of  all  the  cars,  so  that  on  a  long  train  the  cur- 
rent is  collected  at  a  number  of  different  points. 
Where  the  road  crosses  a  highway  the  third  rail  is 
broken,  stopping  at  each  side  of  the  crossing,  and  the 
car  is  allowed  to  drift  over  the  gap  without  current. 
The  continuity  of  the  third-rail  circuit  is  secured  by 
attaching  an  underground  cable  between  the  two  ends 
of  the  third  rail,  and  these  ends  are  built  with  a  down- 
ward curve  so  that  the  shoes,  which  can  only  drop 
slightly  below  their  normal  position,  do  not  make  vio- 
lent contact  with  the  rail,  but  ride  up  on  the  curved 
portion. 

Conduit  System. — The  conduit  system  is  one  in 
which  the  conductors  are  carried  in  a  conduit  under 
the  surface  of  the  street  similar  to  a  cable  railway 
conduit.  Unlike  the  other  system  described  the  COD- 


OVERHEAD    CIRCUIT    AND    THIRD    RAIL.  45 

duit  system  does  not  make  use  of  the  tracks  for  a 
return  circuit,  but  instead  both  the  positive  and  nega- 
tive conductors  are  supported  on  insulators  fastened 
inside  of  the  conduit.  The  current  is  taken  from  these 
conductors  by  means  of  a  trolley  extending  down 
through  a  slot  in  the  surface  of  the  road.  This  under- 
ground trolley  is  called  a  plow.  The  conductors  are 
generally  composed  of  copper  bars  and  the  plow  con- 
tains sliding  contact  pieces  which  rest  on  these  bars. 
One  side  of  the  plow  collects  the  current,  which  is  led 
to  the  controllers  and  motors,  after  which  it  passes 
again  to  the  plow  contact  which  is  in  connection  with 
the  return  circuit. 

This  system  is  in  use  in  New  York  City  and  Wash- 
ington, D.  C.,  and  in  a  few  European  cities  where 
overhead  conductors  are  prohibited.  It  is  very  ex- 
pensive to  build. 

Storage-Battery  Cars. — A  storage-battery  car  is 
one  which  has  electric  current  stored  in  cells  or  bat- 
teries in  the  car,  which  supply  current  to  the  car  motor. 
Such  a  car  can  run  on  any  railroad  track  and  requires 
no  wires  or  conductors  outside  of  itself.  The  storage 
cell  consists  of  plates  of  lead  immersed  in  acid,  and 
these  cells  are  charged  at  the  power  station  by  putting 
them  in  circuit  with  a  dynamo,  the  electric  current 
causing  chemical  changes  in  the  lead.  These  changes 
represent  a  certain  amount  of  electrical  energy,  which 
is  given  out  when  the  batteries  are  connected  to  the 
car  motors.  The  battery  merely  supplies  current  for 
the  car  and  the  controllers  are  similar  to  those  on 
trolley  cars,  and  the  method  of  operation  is  the  same. 
Storage-battery  cars  are  not  very  extensively  used,  as 
the  cost  of  operation  is  considerably  higher  than  that  of 
trolley  cars.  This  is  chiefly  due  to  the  batteries,  which 


46  THE    MOTORMAN. 

are  expensive  to  install  and  which  wear  out  rapidly 
under  the  severe  conditions  of  street  railway  work. 

Electric  Locomotives. — For  the  purpose  of  moving 
long  trains  of  cars,  switching  freight  cars  and  other 
purposes  where  the  power  required  is  so  great  that  the 
motors  cannot  be  mounted  on  the  trucks  of  ordinary 
cars  electric  locomotives  are  used  and  current  is  taken 
from  an  overhead  wire  or  a  third  rail,  as  with  a  trolley 
car.  These  locomotives  (Figure  46)  are  equipped  with 
motors  of  large  capacity  and  their  frames  are  very 
heavy  so  as  to  secure  sufficient  adhesion  to  the  track 


Figure  46 — Large  Electric  Locomotives. 

to  pull  very  heavy  loads.  The  controllers  and  other 
apparatus  on  electric  locomotives  are  similar  to  those 
on  cars  of  ordinary  size,  being  merely  larger  and 
heavier  to  accommodate  the  larger  current  used. 

In  the  great  projects  now  under  way  tending  to- 
ward the  electrification  of  the  more  densely  traveled 
lines  of  our  larger  steam  railway  systems,  the  electric 
locomotive  plays  an  important  part.  Such  locomotives 
are  built  with  steel  bodies  and  trucks  equipped  with 
motors  that  give  the  locomotive  far  greater  hauling 


OVERHEAD    CIRCUIT    AND    THIRD    RAIL. 


47 


capacity  than  can  be  had  with  steam  locomotives. 
Many  inter-urban  railways  also  use  electric  locomotives 
for  handling  freight  cars.  It  should  be  remembered 
that  the  principles  on  which  the  locomotive  depends 
for  its  operation  differ  in  no  way  from  those  governing 
the  operation  of  an  electric  car. 

Overhead  Trolley.— Overhead  trolley  may  be  di- 
vided into  two  general  classes,  according  to  the  method 


Figure  47 — Trolley  Bracket  and  Catenary  Trolley  Construction. 

of  suspension.  The  first  and  more  widely  known  is 
the  common  flexible  suspension.  The  second  is  known 
as  catenary  construction.  (Figures  47  and  48.) 

Each  method  of  suspension  requires  for  the  sup- 
port of  the  overhead  material  one  or  two  lines  of  poles. 
When  one  line  of  poles  is  used  iron  brackets  are  re- 
quired to  support  the  trolley  wires  over  the  center  of 


48 


THE    MOTORMAN. 


the  track,  and  when  two  lines  of  poles  are  used  span- 
wires  across  the  track  from  pole  to  pole  support  the 
trolley  wire.  The  trolley  wire  may  be  either  round  or 
grooved  in  section.  The  round  wire  is  supported  by 
means  of  soldered  or  clinched  ears  and  the  grooved 
wire  by  means  of  mechanical  clamps  which  hook  over 
its  upper  part.  The  ears  in  turn  are  held  by  what  are 
known  as  hangers,  either  insulated  or  non-insulated, 
depending  upon  whether  or  not  a  strain  insulator  is 
placed  in  the  span  or  supporting  wire.  The  span  wires 
usually  are  composed  of  stranded  cable  which  has 
been  galvanized  to  prevent  its  rusting. 


Figure   48 — Anchoring    Catenary   Construction. 

Catenary  Construction.— It  is  essential  for  high- 
speed operation  that  the  trolley  wire  be  supported  in  a 
plane  parallel  with  that  of  the  track  rails.  It  is  also 
essential  that  there  be  very  few  sharp  bends  either 
horizontally  or  vertically  in  the  copper  wire.  With  the 
ordinary  type  of  span  or  bracket  construction  such 
kinks  do  occur,  and  with  a  car  operating  at  high  speed 
there  is  a  tendency  for  the  wheel  to  break  contact  or 
leave  the  wire  at  the  bends  which  occur  under  the  sup- 
ports. The  reason  for  these  bends  existing  is  because 
each  hanger  is  called  upon  to  support  a  section  of  the 
trolley  wire  about  100  feet  long.  To  overcome  this 


OVERHEAD    CIRCUIT    AND    THIRD    RAIL. 


49 


defect  the  catenary  type  of  trolley  construction  is  now 
being  widely  used. 

The  essential  parts  of  this  catenary  method  of 
construction  include  a  messenger  wire,  supported 
at  points  about  125  to  150  feet  apart,  these  supports 


Figure  49 — Catenary  Construction   with   Bridges. 

being  either  span  wires  or  brackets,  as  in  the  ordinary 
type  of  construction,  but  including  an  insulator  on 
which  the  messenger  wire  rests,  so  that  no  path  is 
afforded  the  current  from  the  steel  messenger 
cable  to  flow  through  the  bracket  or  span  wires  and 


50 


THE    MOTORMAN. 


thence  to  the  ground  by  way  of  the  poles.  From 
this  messenger  wire  the  trolley  is  supported  at  a 
fixed  distance  above  the  track  by  means  of  frequent 
vertical  hangers.  Inasmuch  as  the  messenger  itself  is 
insulated  from  the  ground  it  is  wholly  unnecessary  to 
use  insulated  hangers  between  the  trolley  wire  and  the 
messenger;  in  fact,  the  steel  messenger  cable  supple- 
ments the  trolley  wire  as  a  conductor  of  electricity.  It 


Figure  50 — High-Tension    Insulator  and   Tie  Wire. 

is  thus  seen  that  with  the  vertical  hangers  spaced  at 
intervals  of  from  10  to  25  feet  the  trolley  wire  can  be 
supported  with  practically  no  kinks  in  its  under  sur- 
face. Thus  it  is  possible  to  operate  the  cars  at  high 
speeds  and  use  either  the  ordinary  trolley  wheel  or 
one  of  the  sliding-contact  type  which  will  be  described 
later. 

The  catenary  type  of  construction  is  used  most  fre- 
quently with  those  lines   operating  at   high  voltage. 


OVERHEAD    CIRCUIT    AND    THIRD    RAIL.  51 

This  choice  is  made  because  the  trolley  wire  and  mes- 
senger can  so  easily  be  insulated  for  high  voltages. 
It  is  also  an  economical  type  to  use  because  with  the 
aid  of  the  strong  steel  messenger  cable  the  distance  be- 
tween points  of  support  may  be  increased  and  the 
number  of  poles  required  greatly  lessened.  In  the. 
project  of  electrifying  the  New  York  New  Haven  & 
Hartford  lines  near  New  York  City,  steel  bridges  are 
used  to  support  the  messenger  cable,  as  shown  in  Fig- 
ure 49. 

Transmission  Lines.— For  the  sake  of  reliability  of 
service  the  transmission  lines  which  carry  the  current 
from  the  power  station  to  the  substations,  as  earlier  de- 
scribed, should  be  built  in  a  very  substantial  manner. 
These  lines  as  now  built  comprise  wooden  or  steel 
poles  and  steel  towers,  some  of  the  longer  lines  being 
supported  on  steel  windmill  towers.  At  the  top  of 
each  pole  or  tower  are  crossarms  of  wood  which  sup- 
port at  their  extremities  steel  or  wooden  pins  carrying 
large  insulators.  These  insulators  (Figure  50)  must 
be  made  very  carefully  and  of  such  dimensions  and 
materials  as  will  prevent  any  leakage  of  the  current 
between  the  power  wires  and  the  poles. 


CHAPTER  V. 


THE    ELECTRIC    RAILWAY    MOTOR. 

We  are  now  ready  to  look  into  the  details  of  an 
electric  railway  motor.  In  Chapter  II  were  explained 
the  principles  on  which  all  dynamos  and  motors  are 
built.  It  was  found  that  a  motor  is  simply  a  magnet  in 
which  the  magnetism  is  produced  by  the  electric  cur- 
rent, and  in  which  one  part,  called  an  armature,  is 
caused  to  revolve  by  magnetic  attraction  between  it 
and  the  poles  of  other  parts,  called  the  field  magnets. 
It  was  also  learned  how  the  electric  current  is  trans- 
mitted through  wires,  and  what  precautions  are  neces- 
sary to  insulate  or  confine  it  to  the  proper  wires  or 
conductors. 

Let  us  go  more  into  the  details  of  the  internal 
working  of  the  armature  of  the  dynamo  or  motor,  and 
show  the  reason  why  in  one  case  large  engines  are 
used  to  produce  the  electric  current,  while  at  other 
times  the  armature  will  turn  itself  and  give  out  energy. 
In  Figure  29  is  shown  an  armature  complete.  It  con- 
sists of  a  shaft  on  which  is  mounted  an  iron  core 
closely  wrapped  with  wire.  The  ends  of  the  wire  coils 
are  connected  to  the  contact  terminals,  called  the  com- 
mutator, on  which  the  brushes  rest  to  collect  the  cur- 
rent. An  armature  is  represented  in  diagram  in  Fig- 


THE    ELECTRIC    RAILWAY    MOTOR. 


53 


ure  5x.  The  iron  armature  core  A  is  shown  in  the 
form  of  a  ring.  The  winding  B  is  uniformly  wrapped 
around  the  core,  and  every  three  turns  a  wire  is  led  to 
the  commutator  C,  which  is  divided  into  eight  parts 
because  the  winding  shows  eight  coils.  The  number 
of  coils  varies  on  different  kinds  of  armatures. 

Commutator  and  Armature.— The  commutator  con- 
sists of  copper  bars  insulated  from  one  another  by 
mica.  These  bars  form  the  ends  of  the  armature  coils. 
The  bars  are  exposed  to  wear  by  rubbing  contact,  and 


Figure  51. 


Figure  52. 


therefore  are  made  heavier  than  the  wires  so  as  to  last 
a  long  time,  and  to  be  detachable  when  worn  out.  On 
the  commutator  rest  the  brushes  D,  Dl.  If  the  arma- 
ture is  traversed  by  a  current  entering  at  brush  D,  as 
for  instance  when  it  is  used  as  a  motor,  the  current 
passes  to  segment  1,.  and  from  there  through  connect- 
ing wire,  A,  to  the  armature  wire  proper.  Here  it  has 
a  double  pass,  as  shown  by  the  arrows.  Half  the  cur- 
rent will  follow  the  direction  indicated  by  the  arrows 
on  the  upper  half  of  the  ring,  and  the  other  part  of  the 
the  current  will  follow  the  wires  wound  on  the  lower 
half  of  the  armature  core.  The  two  currents  unite 


54  THE    MOTORMAN. 

again  in  the  wire,  E,  enter  segment  5,  pass  through 
brush  Dl,  and  leave  the  armature.  This  flow  takes 
place  in  whatever  position  the  armature  may  be.  For 
instance,  assuming  the  brushes  D,  Dl  stationary  and  the 
armature  turning;  if  the  armature  had  turned  so  far 
around  that  segment  2  would  be  under  the  brush  D, 
then  segment  6  would  be  under  brush  Dl.  The  cur- 
rent would  go  to  the  armature  winding  through  b  and 
leave  it  by  way  of  f.  In  this  way  each  one  of  the  seg- 
ments and  connecting  wires  has  to  perform  its  work 
in  succession.  The  current  in  going  around  the  core 
makes  a  magnet  out  of  the  iron,  as  indicated  by  the 
letters  N,  S. 

For  the  sake  of  convenience  in  understanding,  the 
armature  core  may  be  also  considered  divided  into  two 
half  rings,  as  in  Figure  52,  the  upper  and  lower;  then 
the  current  flowing  around  the  upper  half  makes  it  a 
magnet,  and  similarly  the  current  in  the  lower  half 
will  make  that  half  become  a  magnet.  The  poles  are 
marked  N  and  S.  The  poles  caused  by  each  half  of 
the  current  are  indicated  on  the  ring.  An  N  pole  on 
one  side  and  an  S  pole  on  the  opposite  side  in  each 
half  as  produced,  and  both  together  make  again  one 
N  pole  and  one  S  pole,  but  of  double  the  strength.  As 
long  as  the  brushes  stand  in  this  position  the  magnetic 
poles  will  stay  in  space  in  the  same  position,  however 
much  the  armature  may  rotate,  because  just  as  many 
turns  are  leaving  the  brush  on  one  side  as  are  brought 
under  it  from  the  opposite  side. 

The  iron  ring  wrapped  with  the  armature  wire 
represents  in  reality  two  half-circular  magnets  butting 
together  with  similar  poles.  Whether  these  are  curved 
as  in  Figure  52  or  have  another  form,  for  instance,  be- 
ing straight  bar  magnets,  does  not  alter  anything  in  the 


THE    ELECTRIC    RAILWAY    MOTOR.  56 

nature  of  the  armature.  Xor  is  there,  as  far  as  prin- 
ciple is  concerned,  any  difference  between  a  ring  arma- 
ture, shown  in  Figure  51,  and  a  drum  armature.  An 
armature  made  for  a  street  railway  motor  is  generally 
made  of  thin  discs  mounted  in  a  compact  way  on  a 
shaft  (Figure  53).  All  the  wire  in  this  case  has  to  be 
applied  externally.  It  cannot  be  threaded  through  the 
center  as  in  Figure  51,  but  the  results  are  the  same. 
Figure  54  is  a  diagram  indicating  a  railway  motor  with 
an  iron  core  made  of  discs  and  the  magnetizing  copper 
wire  wound  all  around  the  surface. 


Figure  53 — Armature   Core. 

The  diagram  represents  the  armature  in  section. 
Now  suppose  the  brushes  to  be  set  as  they  are  in  Figure 
51,  then  the  current  flowing  in  the  coils  with  which  the 
armature  core  is  wound  will  cause  N  and  S  poles  in  the 
armature  as  shown.  Current  is  also  sent  through  the 
coils  on  the  field  magnets,  causing  N  and  S  poles  in  the 
magnet  as  indicated.  It  will  be  evident  that  the  S  pole 
of  the  armature  will  endeavor  to  place  itself  in  front 
of  the  N  pole  of  the  field  magnet,  being  attracted  by  it 
and  at  the  same  time  repelled  by  the  S  pole  near  it. 
Similarly  the  N  pole  of  the  armature  will  try  to  get  in 
front  of  the  S  field  pole,  being  attracted  by  this  pole 
and  repelled  by  the  X  pole ;  but,  as  the  brushes  are  sta- 


56 


THE    MOTORMAN. 


tionary,  the  magnetic  poles  S  and  N  of  the  armature 
remain  fixed  in  space  between  the  poles,  while  the  con- 
ductors carrying  the  current  and  the  core  on  which 
they  are  wound  are  turning  in  the  direction  of  the 
arrow  as  long  as  a  current  is  conducted  into  the  arma- 
ture. 

In  a  motor,  therefore,  the  electrical  energy  fur- 
nished by  some  outside  source  causes  rotation  capable 
of  developing  mechanical  energy.  In  a  dynamo  it  is 
just  the  opposite.  There  is  no  electrical  energy  given: 
it  has  to  be  produced.  The  wire  coils  passing  in  front 
of  the  magnet  poles  generate  current. 


Figure  54. 


Figure  55. 


Figure  55  illustrates  this  action.  The  field  magnet 
N  S  changes  the  armature  into  a  magnet  with  the  poles 
as  indicated,  the  S  pole  of  the  armature  approximately 
facing  the  N  pole  of  the  field  and  the  N  pole  of  the 
armature  nearly  facing  the  S  pole  of  the  field  magnet. 
There  exists  mutual  attraction  between  the  armature 
and  the  field  magnet.  To  generate  a  current,  the  arma- 
ture must  be  turned  between  the  energized  field  magnet 
poles,  which  is  equivalent  to  attempting  the  pulling 
away  of  the  armature  poles  from  under  the  field  poles. 
This  we  know  from  the  first  experiment  mentioned  in 
the  book  means  the  expenditure  of  energy. 

Parts  of  Railway  Motor. — We  can  now  look  more 
intelligently  at  the  parts  of  a  railway  motor  than  we 


THE    ELECTRIC    RAILWAY    MOTOR. 


Figure  56 — Interior  of  Railway  Motor. 


58  THE    MOTORMAN. 

could  at  first.  Figure  56  shows  a  railway  motor  with 
its  frame  opened,  giving  a  view  of  its  interior  parts. 
The  armature,  A,  is  mounted  upon  a  shaft  and  at  one 
end  of  the  armature  is  the  commutator  C,  consisting 
of  a  cylinder  of  insulated  copper  bars,  to  which  the 
ends  of  the  armature  coils  are  connected.  Surround- 
ing the  armature  are  four  field  magnets,  or  poles,  P, 
around  which  are  wound  coils  of  wire  to  magnetize 
them  for  the  purpose  previously  explained.  The 
brushes,  B,  conduct  the  current  to  and  from  the  arma- 
ture through  their  contact  with  the  commutator.  These 
brushes  consist  of  carbon 
blocks  which  are  held  in 
brush  holders  (Figure  57) 
and  pressed  against  the 
commutator  by  springs. 
The  principal  parts  of  an 
electric  railway  motor 
are :  The  armature,  which 
has  been  described  and  is  Figure  57_Brush  Hoider. 
mounted  on  a  steel  shaft; 

the  shell  or  case,  which  is  a  large  box-like  casting  of 
soft  steel  supporting  on  its  interior  the  field  magnets, 
and  the  gears  which  transmit  the  turning  power  from 
the  armature  shaft  to  the  car  axle. 

The  path  of  the  current  through  the  motor  is  as 
follows :  Starting  at  one  of  the  brushes  the  current 
passes  through  all  the  coils  of  wire  upon  the  armature, 
beginning  at  whatever  commutator  bar  the  brush  hap- 
pens to  rest  upon,  and  comes  out  upon  another  com- 
mutator bar  under  the  second  brush.  From  this  brush 
the  current  is  led  through  all  the  field  coils  wound 
around  the  poles  surrounding  the  armature,  and  this 
completes  the  circuit  through  the  motor.  With  the 


THE    ELECTRIC    RAILWAY    MOTOR.  5S 

current  flowing  through  both  the  armature  and  the  field 
coils,  both  the  armature  and  the  field  become  magnets, 
and  each  attracts  the  other  in  such  a  way  as  to  cause  the 
armature  to  turn  as  previously  explained.  To  reverse 
the  direction  in  which  the  armature  revolves,  which  re- 
verses the  direction  of  the  car,  it  is  only  necessary  to 
change  the  direction  in  which  the  current  flows  through 
the  armature,  allowing  the  current  to  flow  through  the 
fields  in  the  same  direction  as  before;  or,  we  can  also 


Figure  58 — Motor  on   Axle. 

reverse  the  direction  of  revolution  by  permitting  the 
current  to  flow  in  the  same  direction  through  the  arma- 
ture and  reversing  its  direction  through  the  field  coils. 
If  the  armature  current  is  reversed  the  magnetism  in  the 
armature  is  reversed,  the  north  pole  becoming  a  south 
pole  and  the  south  pole  a  north  pole.  In  order  to  re- 
verse the  current  in  the  armature  the  wires  from  the 
armature  brushes  are  led  to  the  controller  independ- 
ently from  the  terminals  of  the  field  coils,  so  that  the 
connections  of  the  armature  terminals  can  be  reversed 


60  THE    MOTORMAN. 

at  the  controller  when  it  is  desired  to  reverse  the 
direction  of  rotation  of  the  motor.  For  this  reason 
there  will  always  be  at  least  four  wires  leading  out 
from  the  motor. 

An  electric  railway  motor  mounted  on  an  axle  be- 
tween the  car  wheels  is  shown  in  Figure  58.  For  the 
sake  of  clearness  one  pair  of  wheels  and  axle  have 
been  taken  away  from  the  truck.  The  motor  consists 


Figure  59 — End  View  of  Motor  and  Gears. 

of  two  principal  parts :  the  outer  case,  which  is  called 
the  field  magnet  and  which  is  stationary,  and  an  inner 
rotating  part  called  the  armature.  Figures  58  and  59 
give  a  general  idea  of  the  appearance  of  the  motor  and 
may  be  referred  to  together.  On  one  end  of  the  arma- 
ture shaft  6  is  keyed  a  pinion  B,  as  shown  in  Figure  59, 
but  in  service  the  pinion  and  the  gear  into  which 
it  meshes  are  covered  by  a  casting  as  Bl  C1  in  Figure 
58.  This  pinion  meshes  with  a  gear  which  is  fastened 
on  the  car  axle.  The  car  axle  passes  through  the  bear- 


THE    ELECTRIC    RAILWAY    MOTOR. 


01 


ing  5,  as  shown  in  Figures  59  and  60.  Both  solid  and 
split  gears  (Figures  61  and  62)  are  used.  The  split 
gears  are  more  easily  handled  for  repairing,  biit  the 
solid  gears,  which  are  pressed  on  the  axles  by  hy- 
draulic power,  wear  longer. 

The  manner  in  which  the  car  is  propelled  will  now 
be  made  clear.  In  starting  the  car  a  current  is  sent 
into  the  motor  which  causes  the  armature  to  revolve 


Figure  60 — Exterior  of  Motor. 

and  with  it  the  pinion  B.  This  pinion  meshes  with  the 
teeth  of  the  gear  C  and  turns  it  in  a  direction  opposite 
to  which  the  pinion  rotates.  (See  Figure  59.)  As 
the  pinion  B  is  much  smaller  in  diameter  than  the  gear 
C,  the  car  axle  to  which  C  is  rigidly  attached  makes 
a  less  number  of  revolutions  than  does  the  pinion  which 
drives  it.  In  this  way  the  power  developed  in  the 
motor  is  transmitted  through  the  gears  to  the  car  axle 


62  THE    MOTORMAN. 

and  the  speed  of  the  latter  is  much  less  than  that  of 
the  motor  armature. 

Returning  to  Figure  59,  if  the  power  admitted  to 
the  motor  turns  the  armature  shaft  6  and  pinion  B  in 
the  direction  indicated  by  the  arrow,  then  the  gear  C 
will  revolve  in  the  opposite  direction  and  the  car  wheel 
2  will  move  from  right  to  left  as  indicated  by  the  arrow. 
The  function  of  the  casing  B1  is  to  protect  the  pinion 
and  gears  from  dirt  and  mechanical  injury.  Some  gear 


Figure  61 — Solid  Gear.  Figure  62 — Split  Gear. 

cases  are  made  of  wood  and  steel,  as  shown  in  Figure 
63.  If  filled  with  a  heavy  grease  the  gears  are  thus 
lubricated  and  preserved,  and  at  the  same  time  the 
noise  which  they  make  in  running  by  this  means  is 
greatly  reduced.  In  all  of  the  motors  illustrated  a  lid 
will  be  noticed  over  the  commutator  end  of  the  frame 
where  the  brushes  are  located.  These  lids  are  readily 
removed,  and  their  object  is  to  facilitate  inspection 
of  the  commutator  and  brushes. 

It  will  be  noticed  that  all  of  the  motors  illustrated 
have  their  field  casings  designed  so  as  to  entirely  en- 


THE    ELECTRIC    RAILWAY    MOTOR.  63 

close  the  interior  parts,  and  all  the  joints  of  the  outer 
frame  are  made  tight  enough  to  be  practically  water- 
proof. Water  and  dirt  would  readily  be  thrown  into 
the  motor  from  the  car  wheels  if  the  parts  were  not 
tightly  enclosed,  but  by  having  the  motor  case  close 
tightly  the  windings  are  protected  from  water,  which 
would  injure  them. 


Figure  63 — Gear  Case. 

Figures  64  and  65  show  two  views  of  a  car 
motor.  Figure  64  shows  the  frame  closed  about  the 
armature  ready  for  operating.  Figure  65  shows  the 
lower  frame  of  the  motor  dropped,  with  the  armature 
in  the  lower  position.  This  method  of  dividing  field 
magnets  horizontally  through  the  bearings  and  fasten- 
ing the  lower  part  at  one  side  by  means  of  hinges 
provides  for  the  inspection  and  repairs  of  the  interior 
parts  of  the  motor. 


Figure  64 — View  of  Motor  from   Axle    End. 


Figure  65 — Motor  with  Case  Open. 


THE    ELECTRIC    RAILWAY    MOTOR.  65 

Motor  Suspension. — In  supporting  motors  upon  car 
trucks  one  side  of  the  motor  is  held  in  position  by  the 
bearings  resting  on  and  around  the  car  axle.  The  other 
side  of  the  motor  is  not  usually  fastened  rigidly  to  the 


Figure  66 — Cradle   Suspension. 


frame  of  the  truck,  but  has  springs  placed  at  some  point 
between  the  motor  and  the  frame  in  order  to  avoid  the 
sudden  jar  which  would  be  occasioned  in  starting  the 
motor  if  it  were  rigidly  connected.  These  springs  also 
serve  to  "greatly  increase  the  life  of  the  gear  wheels, 
as  part  of  the  shock  in  starting  is  taken  up  by  the 


Figure  67 — Parallel   Bar  Suspension. 

springs,  without  which  the  teeth  would  be  liable  to  be 
stripped  from  the  gears.  Figures  66,  67  and  68  repre- 
sent the  same  motor  with  different  styles  of  suspension. 


66  THE    MOTORMAN. 

Figure  66  shows  what  is  called  the  cradle  suspension, 
which  consists  of  an  iron  bar  resting  on  heavy  springs 
which  in  turn  rest  on  the  truck.  This  method  is  de- 
signed to  relieve  the  motor  bearings  of  the  weight  of 
the  motor,  which  being  suspended  in  the  line  of  its 
center  of  gravity  is  supported  without  undue  strains. 
Figure  67  shows  the  parallel  bar  suspension  and  Figure 
68  the  nose  suspension.  The  latter  is  the  one  most 
commonly  used. 

Types  of  motors  differing  in  some  respects  from 
those  previously  illustrated  are  shown  in  Figures  69 


Figure  68 — Nose   Suspension. 

and  70.  Figure  69  is  known  as  the  box-frame  type 
and  differs  from  the  split-frame  type  in  that  the 
magnet  frame  is  cast  in  practically  one  piece,  forming 
a  cube  with  well-rounded  corners  and  large  openings 
at  each  end  into  which  the  frames  carrying  the  bear- 
ings for  the  armature  shaft  are  bolted.  The  armature 
is  put  in  place  or  removed  through  these  end  open- 
ings in  the  frame. 

Motors  of  this  type  are  mounted  or  moved  from 
the  truck  by  means  of  a  crane  from  above  when  the 
truck  is  out  from  under  the  cars,  and  no  track  pit  is  re- 


THE   ELECTRIC   RAILWAY    MOTOR.  67 


Figure  70 — Motor  with    Diagonally  Split   Frame. 


68  THE   MOTORMAN. 

quired.  In  order  to  facilitate  removing  the  armatures 
from  these  motors  a  special  tool  is  provided,  upon  which 
the  motor  is  mounted.  The  armature  shaft  is  centered 
on  this  tool  and  by  removing  the  bolts  from  one  of 
the  frame  heads  and  moving  the  motor  frame  to  one 
end  of  the  tool  by  means  of  the  hand  wheel,  the  arma- 
ture is  left  entirely  exposed  and  mounted  upon  centers, 
where  it  may  be  readily  inspected  or  repaired.  A 
more  recent  way  is  to  stand  the  motor  case  on  end, 


Figure  71 — Interpole  Motor. 

when  by  use  of  air  or  hydraulic  hoists  the  armature  is 
lifted  out. 

Interpole  Motors. — Probably  the  most  promising 
improvement  in  direct-current  railway  motors  for  many 
years  is  the  introduction  of  the  interpole  or  commutat- 
ing  pole  motor.  The  commutation  of  high-voltage  cur- 
rent in  railway  motors  has  always  been  a  most  diffi- 
cult problem  for  the  designers  of  such  machinery  to 
solve  and  the  care  of  commutators  and  brushes  forms 
no  small  part  of  the  duties  of  the  mechanical  and  elec- 
trical force  of  a  railway  company. 


THE    ELECTRIC    RAILWAY    MOTOR.  69 

Sparking  on  a  commutator  bites  away  a  small 
amount  of  copper  and  carbon  at  each  spark,  but  does 
not  affect  the  mica  between  segments.  If  the  sparking 
is  continued,  the  copper  is  soon  eaten  down,  thus  leav- 
ing the  mica  sticking  up.  This  ''high  mica"  in  turn 
makes  the  sparking  worse  and  causes  a  general  rough- 
ening of  the  commutator,  flattening  of  the  bars,  etc., 
with  consequent  rapid  wear  of  the  brushes,  which  fills 
the  motor  with  carbon  and  copper  dust,  and  sometimes 
causes  it  to  flash,  ground,  etc.  Milling  down  the  mica 
below  the  copper  prevents  some  of  this  trouble,  but 
does  not  go  to  the  root  of  the  matter. 

In  service  a  railway  motor  does  not  run  contin- 
uously with  power  on,  but  the  time  that  it  is  operating 
under  load  is  varied  by  a  certain  amount  of  coasting 
and  stopping.  During  this  no-load  running  the  rough- 
ening which  has  been  caused  by  the  action  of  the  cur- 
rent is  partly  corrected  by  the  scouring  and  polishing 
effect  of  the  brushes  without  load.  In  many  cases  the 
scouring  action  predominates  so  that  the  commutators 
remain  bright  and  clean  and  take  on  a  good  polish. 

The  purpose  of  commutating  poles  is  to  reduce 
sparking.  The  commutating  pole  is  an  intermediate 
pole  of  small  dimensions,  placed  between  the  main  field 
magnet  poles.  It  is  used  for  reversing  the  direction  of 
the  current  in  the  armature  coils  when  they  are  short- 
circuited  by  the  brushes.  Thus,  by  magnetically  in- 
ducing a  current  of  proper  direction  in  the  short-cir- 
cuited coils,  the  sparking  at  the  commutator,  resulting 
from  the  "kick"  of  the  short-circuited  coils,  is  avoided. 
Since  the  direction  of  the  current  in  the  commutating 
pole  coils  is  reversed  when  the  current  in  the  armature 
is  reversed,  they  are  equally  effective  when  the  motor 
is  reversed. 


70 


THE    MOTORMAN. 


These  motors  are  manufactured  in  six  sizes,  rang- 
ing from  50  to  200  horsepower.  They  are  built  for  a 
standard  of  600  volts. 

The  field  magnet  frames  of  these  motors  are  sim- 
ilar in  design  to  those  of  the  standard  railway  motors, 
with  the  exception  that  the  commutating  poles  are  in- 
serted between  the  main  pole  pieces,  as  shown  in  Fig- 


Figure  72 — Interior  of  Interpole  Motor. 

ure  72.     The  frames  are  made  in  both  the  split  and 
box  types. 

The  Single-Phase  Motor. — The  single-phase  railway 
system  accomplishes  the  same  results  in  car  movement 
that  are  secured  by  the  use  of  direct-current  equip- 
ments, but  it  does  this  in  many  cases  with  less  first 
cost,  less  operating  expense,  increased  flexibility  and 
greater  simplicity. 

At  the  substations  the  alternating-current  power 
which  is  received  from  the  generators  is  merely  re- 


THE    ELECTRIC    RAILWAY    MOTOK.  71 

duced  in  voltage  by  transformers  and  supplied  at  once 
to  the  cars,  instead  of  being  changed  into  direct  cur- 
rent by  transformers  and  rotary  converters.  The 
equipment  of  such  a  substation  is  quite  simple  and  may 
be  left  without  attendants. 

One  of  the  fundamental  characteristics  of  alternat- 
ing current  ii  the  readiness  with  which  it  can  be  trans- 
formed from  one  voltage  to  another.  Where  alternat- 
ing-current motors  are  used,  therefore,  it  is  not  neces- 
sary as  with  direct  current  to  supply  power  to  the  cars 
at  the  voltage  of  the  motors,  but  by  the  use  of  a  trans- 
former on  the  car  the  voltage  of  the  trolley  and  that  of 
the  motors  may  have  any  desired  ratio.  As  it  is  en- 
tirely feasible  to  employ  a  voltage  of  11,000  (which 
permits  the  distribution  of  a  large  amount  of  power 
with  a  very  small  current)  on  a  properly  insulated 
trolley  wire,  the  single-phase  system  affords  means  of 
operating  even  the  heaviest  cars  or  trains  from  an  or- 
dinary trolley  wire  of  moderate  size  with  no  additional 
feeders. 

The  single-phase  railway  motor  does  not  involve 
any  particularly  new  or  mysterious  principle,  but  de- 
pends for  its  operation  upon  an  extension  of  the  well- 
known  fact  that  reversing  the  current  at  the  terminals 
of  a  series  direct-current  motor  does  not  reverse  the 
direction  of  rotation  or  interfere  with  the  operation. 
This  principle  holds  good  no  matter  whether  the  cur- 
rent is  reversed  once  every  hour  or  once  every  minute. 
Since  an  alternating  current  gives  merely  the  same 
general  effect  as  a  very  rapid  and  continuous  reversal 
of  a  direct  current  the  ordinary  direct-current  railway 
motor  rotates  if  suitable  alternating  current  is  applied 
to  it. 

The  single-phase  motor  (Figure  73)   ordinarily  is 


72 


THE    MOTORMAN. 


wound  for  a  voltage  of  from  200  to  250  instead  of 
500  or  550,  as  in  the  ease  of  direct-current  motors. 
The  larger  currents  which  must  be  handled  on  this 
account  necessitate  greater  brush  capacity  than  in  di- 
rect-current motors,  so  that  four  brush  arms  ordinarily 
are  required  with  a  four-pole  motor  or  six  with  a  six- 
pole  motor. 

The  standard  trolley  voltage  for  single-phase  op- 


Figure  73 — Single-Phase  Motor. 

eration  is  6,600,  although  voltages  of  3,300  and  11,000 
are  also  employed  in  some  cases. 

To  reduce  the  trolley  voltage  for  use  at  the  motors 
an  oil-insulated,  self-cooling  "auto-transformer"  is 
used.  As  with  direct-current  motors,  the  speed  of  the 
single-phase  motor  varies  with  the  voltage  at  its  ter- 
minals, and  the  motor  is  controlled  in  this  way.  In 
order  to  get  a  variable  voltage  for  this  purpose,  how- 


THE    ELECTRIC    RAILWAY    MOTOR.  73 

ever,  it  is  not  necessary,  as  in  direct-current  practice, 
to  change  the  grouping  of  the  motors,  or  to  introduce 
resistance  into  the  circuit,  but  simply  to  connect  the 
motors  to  different  taps  on  the  auto-transformer. 

The  qualities  which  make  the  single-phase  motor 
suitable  for  operation  on  alternating  current  make  it 
operate  equally  well  on  direct  current  of  the  proper 
voltage.  It  is  often  desirable  to  obtain  the  benefits 
of  single-phase  operation  with  cars  which  for  a  part 
of  their  route  must  run  over  the  same  tracks  and  use 
the  same  power  as  direct-current  cars,  and  by  connect- 
ing two  or  more  single-phase  motors  in  series  for  such 
operation  they  can  readily  be  arranged  to  run  from  a 
550-volt  trolley  wire,  as  well  as  from  a  6.600  or  other 
high-voltage  one. 


CHAPTER  VI. 


CAR    WIRING    AND    PARTS. 

We  will  now  trace  the  electrical  circuit  through  the 
car.  The  current,  as  we  know,  conies  from  the  power 
station  through  the  feed  wires  and  troll ey  wire,  and 
flows  through  the  trolley  wheel  down  the  trolley  pole 
to  the  trolley  base. 


Figure  74 — Roller-Bearing   Trolley   Base. 

There  are  many  styles  of  trolley  bases.  In  Figures 
74  and  75  two  forms  are  shown.  The  trolley  wire  is 
generally  attached  to  the  iron  base  below.  The  springs 
are  employed  for  the  purpose  of  causing  an  upward 
pressure  en  the  trolley  pole,  which  is  not  shown.  The 
pole  can  be  removed  from  the  trolley  base  and  is  held 


CAR    WIRING    AND    PARTS.  75 

adjustably  in  a  socket.  A  great  range  of  movement  is 
necessary  in  the  springs  and  trolley  pole,  as  the  trolley 
wire,  suspended  in  the  air,  cannot  be  held  at  the  same 
height  over  all  the  course  of  travel.  For  instance,  at 
railroad  crossings  it  is  placed  much  higher  so  as  not 
to  interfere  with  the  railroad  service  and  brakemen  who 
may  be  standing  on  the  roofs  of  the  cars ;  again  it  may 
be  much  lower  in  other  places,  such  as  bridges  and 
tunnels. 

One  type  of  trolley  base,  shown  in  Figure  74,  is 
mounted  on  an  anti-friction  turntable,  which  consists 
of  four  roller-bearing  wheels,  revolving  between  chilled 


Figure  75 — Trolley  Base  and  Tension  Springe. 

surfaces,  above  and  below.  It  is  self-oiling  and  weath- 
erproof in  every  respect  and  is  also  constructed  so  that 
should  the  pole  be  turned  over  in  the  opposite  posi- 
tion, the  tension  would  be  the  same.  The  sleeve  in 
which  the  trolley  pole  is  secured  is  two  feet  long,  which 
length  gives  the  trolley  pole  a  reinforcement.  The 
base  is  constructed  so  as  to  lock  down  and  permit  of 
changing  the  pole  while  in  a  horizontal  position.  The 
trolley  pole  is  a  long  iron  pipe-like  pole  on  the  end  of 
which  is  located  the  "trolley."  This  trolley  wheel, 
which  consists  of  brass  or  special  metal,  is  generally  a 
small,  narrow  wheel  with  projecting  flanges.  On  in- 


76  THE    MOTORMAN. 

terurban   roads   where   cars   are   run   at   high   speeds 
larger  wheels,  six  inches  in  diameter,  are  used. 

Pantagraph  Trolley.— For  use  on  high-speed  roads 
operating  at  high  pressures  a  pneumatically  operated 
pantagraph  trolley  has  been  devised  which  can  readily 
be  raised  or  lowered  by  the  motorman  without  leaving 
his  cab.     In  trains  of  several  motor  cars,  moreover, 
the      trolleys      on 
the     entire     train 
may      be      simul- 
taneously     c  o  n  - 
trolled    from    any 
one    point.      This 
trolley  is  normal- 
ly    held     against 
the  wire  by  means 
of    a    spring,    but 
is  lowered  and  au- 
tomatically locked 
down   by  the   ap- 
plication   of   com- 
pressed   air.      Ap- 
plication    of     the  Fjgure  76_sliding  Bow  Trolley. 
air      to      another 
point  will  then  unlock  the  trolley  and  allow  it  to  rise. 

In  the  types  of  trolley  shown  in  Figures  76  and 
78  the  current  is  collected  by  a  rubbing  or  sliding  con- 
tact bar. 

Third-Rail  Shoes.— Where  the  third-rail  method  is 
used  for  distributing  the  current  along  the  track  to 
the  cars  as  we  have  described  in  Chapter  IV.  there  are 
shoes  provided  to  make  an  electrical  connection  be- 
tween the  car  wiring  and  the  third  rail.  These  shoes 


CAR    WIRING    AND    PARTS. 


77 


Figure  77 — Pantagraph  Trolley  Lowered. 


Figure  78 — Pantagraph  Trolley  Raised. 


78 


THE    MOTORMAN. 


are  mounted  on  a  bar  (Figure  79),  which  is  fastened 
between  the  two  journal  boxes  so  that  it  does  not  rise 
and  fall  as  the  car  moves  over  rough  track,  but  always 
remains  the  same  distance  from  the  track  rail  and  the 
third  rail.  The  shoe  is  of  such  a  shape  and  size  that 
when  held  by  springs  or  its  own  weight  it  makes  a 


Figure  79 — Attachment  of  Third- Rail  Shoe. 

continuous  sliding  contact  on  the  head  of  the  third 
rail  as  the  car  moves  along.  One  of  the  important  ad- 
vantages in  the  use  of  the  third  rail  is  that  these  steel 
shoes  last  for  a  very  long  time  and  do  not  need  re- 
newing as  often  as  trolley  wheels.  There  is  also 
another  advantage — that  no  attention  need  be  paid  to 
the  shoes  by  the  car  crew  when  it  is  desired  to  switch 
the  car  from  one  track  to  another  or  to  back  it  in 
the  yards. 


CAR    WIRING    AND    PARTS.  79 

All  current  collectors,  of  whatever  type  they  may 
be,  are  insulated  from  the  car  body  or  trucks  and  the 
path  of  the  current  from  the  connections  with  the 
third-rail  shoe  or  the  sliding  pantagraph  trolley  is 
the  same  as  that  from  the  ordinary  wheel-and-pole 
trolley. 

Main  Switches.— From  the  trolley  base  a  wire  con- 
ducts the  current  to  the  canopy  switches  or  circuit- 
breakers  over  the  platforms  and  passing  through  these 


Figures  80  and  81 — Overhead  Circuit- Breaker. 

it  flows  through  another  wire,  generally  concealed  in 
a  corner  post  of  the  car,  to  a  fuse  box.  The  canopy 
switch  (Figures  80  and  81)  is  also  sometimes  called  the 
main  motor  switch,  the  overhead  switch  or  the  auxiliary 
switch.  These  switches  are  generally  provided  with 
what  is  known  as  a  blow-out  magnet  coil,  for  the  pur- 
pose of  blowing  out  the  arc  when  the  switch  is  opened. 
Automatic  circuit-breakers  have  recently  been 
used  to  a  large  extent  to  take  the  place  of  the  fuse  and 
canopy  switch.  They  are  preferable  for  a  number  of 
reasons,  the  chief  of  which  is  that  they  may  be  ar- 


80 


THE    MOTORMAN. 


ranged  to  break  the  circuit  when  the  current  exceeds 
any  predetermined  amount  with  much  more  accuracy 
than  a  wire  fuse,  and  they  are  thrown  into  circuit 
again  simply  by  the  movement  of  a  handle  without  the 
necessity  of  replacing  any  of  the  parts,  as  with  the 
fuse.  There  are  a  number  of  circuit-breakers  on  the 
market,  all  designed  practically  upon  the  same  prin- 
ciple, one  of  which  is  shown  in  Figure  82. 


Figure  82 — Circuit- Breaker  Cover  Open. 

The  principal  part  of  the  automatic  circuit-breaker 
is  a  switch  which  closes  against  a  spring,  and  which 
is  held  in  its  closed  position  by  means  of  a  trip.  In  the 
circuit  of  the  machine  is  placed  a  magnetic  coil,  the  pur- 
pose of  which  is  to  attract  an  armature  whose  movement 
releases  the  trip,  permitting  the  spring  to  throw  the 
contact  surfaces  apart  and  break  the  circuit.  The 
cause  of  the  armature  being  attracted  and  the  trip  re- 
leased is  this :  The  magnet  coil  is  so  wound  that  with  a 
normal  amount  of  current  passing  through  the  magnet 


CAR    WIRING    AND    PARTS.  81 

is  not  strong  enough  to  attract  the  armature,  but  the 
moment  an  excessive  amount  of  current  is  used  the 
strength  of  the  magnet  is  correspondingly  increased,  so 
that  the  armature  is  attracted  and  the  trip  released, 
which  opens  the  circuit. 

Fuses. — The  next  piece  of  apparatus  in  the  circuit 
is  the  fuse  box,  which  is  a  device  for  protecting  the 
motors  from  an  excessive  flow  of  current.  All  of  the 
current  flowing  through  the  car  motors  passes  through 
one  of  these  fuse  boxes,  of  which  there  are  several 
styles  on  the  market.  The  simplest  fuse  consists  of  a 
piece  of  soft  wire  generally  made  of  some  alloy  of 
lead  having  a  low  current  carrying  capacity.  This 
piece  of  fuse  wire  will  melt  and  open  the  electric  cir- 
cuit whenever  the  current  flowing  through  the  motors 
is  of  such  an  amount  as  might  burn  the  insulation  on 
the  coils  of  the  armature  or  the  field  magnet.  When 
too  much  current  is  permitted  to  flow  through  any  wire 
it  becomes  heated,  and  the  greater  the  amount  of  cur- 
rent the  hotter  the  wire  becomes.  If,  therefore,  some- 
thing should  happen  on  the  car  to  allow  too  much  cur- 
rent to  flow  through  the  motors  the  wire  upon  their 
armatures  and  fields  would  become  heated  so  as  to 
burn  the  insulation  upon  them,  and  eventually  would 
be  melted  if  the  circuit  were  not  protected  with  a  fuse 
which  would  melt  when  the  current  exceeded  a  cer- 
tain safe  amount.  The  fuse  is  frequently  a  short  length 
of  metal  connected  between  two  binding  posts,  and  of 
a  material  that  will  melt  at  a  very  low  temperature, 
although  sometimes  a  small  copper  wire  is  used.  When 
copper  is  used  it  must  be  of  a  size  much  smaller  than 
any  of  the  other  wires  on  the  car,  so  that  it  will  melt 
before  any  other  of  the  wires  in  the  circuit  can  get 
dangerously  hot. 


82  THE    MOTORMAN. 

In  addition  to  the  bare  wire  fuses  just  described, 
there  are  various  covered  fuses  such  as  those  types 
shown  in  Figure  84  and  Figure  85.  These  enclosed 
fuses  have  a  fusible  conductor  which  is  enclosed  in 
a  tube,  and  around  the  conductor  is  a  special  filling 
which  prevents  any  arc  or.  flash  under  short  cir- 
cuits. A  fuse  of  this  kind  is  a  great  improvement 
over  the  old-fashioned  bare  wire  fuses.  They  do  not 
blow  with  the  loud  report  and  heavy  flash  which  ac- 
company the  blowing  of  a  bare  fuse.  They  are  also 
of  advantage  in  not  blistering  the  varnish  and  paint 


Figure  83 — Open  Fuse.  Figure  84 — Closed  Fuse. 

of  the  car,  which  frequently  happens  with  the  uncov- 
ered fuse.  Another  advantage  of  these  fuses  is  that 
they  are  inserted  in  the  fuse  box  by  simply  pushing  the 
tube  into  its  seat  between  clamping  springs,  and  there 
are  no  thumbscrews,  the  manipulation  of  which  in  the 
old  kind  is  a  difficult  matter  in  severe  weather. 

Lightning  Arresters. — The  next  device  on  the  car 
to  which  the  current  is  led  is  the  lightning  arrester. 
This  is  a  device  to  deflect  lightning  from  the  circuit  to 
the  ground  before  it  has  an  opportunity  to  reach  the 
motors  or  other  electrical  apparatus  on  the  car.  There 


CAR    WIRING    AND    PARTS.  83 

is  a  strong  tendency  for  a  lightning  discharge  to  take 
the  shortest  and  most  direct  path  to  the  ground,  and 
it  will  readily  arc  over  a  small  gap  or  air  space  or 
will  pierce  through  insulating  materials  to  the  ground. 
If  it  were  not  for  the  lightning  arrester,  the  lightning 
would  frequently  jump  through  the  insulation  of  the 
armatures  or  field  magnets  of  the  car  motor;  and  while 
the  very  small  current  of  the  lightning  discharge  would 
do  no  harm  of  itself,  the  arc  which  it  would  establish 


Figure  85 — Closed  Fuse. 

in  jumping  to  the  ground  would  be  followed  by  the 
line  current  from  the  trolley  wire,  which  would  burn 
out  the  windings  immediately. 

The  tendency  of  lightning  to  jump  to  the  ground 
by  the  shortest  path  is  the  principle  upon  which  almost 
all  lightning  arresters  are  designed.  These  devices 
usually  consist  of  some  arrangement  whereby  the  light- 
ning easily  can  pass  down  the  wire  across  to  the 
ground  by  jumping  between  points  set  a  small  fraction 


84 


THE    MOTORMAN. 


of  an  inch  apart.  Various  provisions  are  made  by 
different  manufacturers  to  prevent  the  current  from 
the  power  station  from  following  the  lightning  when  it 
is  deflected  to  earth.  Figure  86  shows  a  diagram  of 
the  connections  of  the  lightning  arrester.  One  ter- 
minal is  connected  to  the  wire  from  the  trolley,  the 
other  to  the  motor  truck  and  thence  to  the  ground. 
The  lightning  jumps  across  between  the  points  and  is 
thus  led  to  the  earth. 


i 


Figures  86  and  87 — Lightning  Arrester. 

Figure  87  shows  a  complete  arrester.  The  two  car- 
bon points  are  indicated  by  an  arrow,  between  which 
the  lightning  jumps  on  its  way  to  earth.  In  order  to 
open  this  special  circuit  after  the  lightning  has  passed, 
so  that  the  current  from  the  dynamo  cannot  follow  by 
the  same  path  that  is  taken  by  the  lightning  to  earth,  the 
circuit  to  the  lightning  arrester  is  automatically  broken 
by  an  electro-magnet  which  pulls  the  two  carbons  apart 
as  soon  as  current  flows  through  the  coil  C.  It  will  be 


CAR    WIRING    AND    PARTS.  85 

seen  that  the  circuit  of  the  lightning  arrester  or  by- 
pass is  constantly  open  except  when  temporarily 
closed  while  the  lightning  flash  crosses  it,  and  even 
then  it  is  a  circuit  of  very  high  resistance.  It  is  there- 
fore clear  that  even  though  the  lightning  arrester  is 
connected  to  the  trolley  wire,  yet  no  current  from  the. 
trolley  line  goes  through  it.  A  kicking  coil,  Figure  88, 
is  used  in  connection  with 
the  lightning  arrester. 
An  inductive  resistance 
such  as  this  coil  is  the 
only  resistance  that  offers 
hindrance  to  the  passage 

Figure   88— Kicking    Coil. 


Figures  89  and  90 — Lightning  Arresters. 

of  static  electricity,  known  as  lightning,  and  yet  allows 
the  trolley  current  to  flow  to  the  motors.  The  kicking 
coil,  Figure  88,  is  put  in  the  circuit  immediately  after 
the  lightning  arrester  and  its  inductive  resistance 
tends  to  drive  the  discharge  through  the  arrester  be- 
fore it  reaches  the  motors  or  other  apparatus. 


THE  MOTORMAN. 


CAR    WIRING    AND    PARTS.  87 

After  the  line  current  has  passed  the  point  where 
the  lightning  arrester  is  connected,  it  flows  through 
what  is  called  the  choke,  or  kicking  coil,  previously 
mentioned.  The  object  of  this  is  to  aid  in  making  it 
difficult  for  the  lightning  to  flow  toward  the  motors, 
owing  to  an  inductive  kick  in  the  spiral  winding,  and. 
to  increase  the  liability  of  its  going  to  ground  through 
the  lightning  arrester  (Figure  90). 

After  leaving  the  choke  coil  the  current  passes 
through  a  heavy  wire  connecting  with  the  controllers 
on  the  platform.  As  will  be  explained  in  a  later  chap- 
ter, these  controllers  comprise  sets  of  switches  which 
are  turned  by  the  handle  on  top  operated  by  the  motor- 
man.  At  different  points  in  the  revolution  of  this 
handle  the  different  switches  in  the  controller  connect 
the  motors  in  various  ways  with  sets  of  resistance 
which  are  mounted  under  the  car  floor.  After  passing 
the  controller  the  current  is  led  through  the  resistance 
and  to  one  of  the  brushes  in  the  motor  case.  From 
this  brush,  as  we  have  already  seen  in  an  earlier  chap- 
ter, the  current  passes  through  the  commutator  bars 
and  through  the  armature  back  to  opposite  commu- 
tator bars  and  out  through  a  brush  on  the  other  side 
of  the  controller  from  where  it  entered.  From  this 
brush  the  current  passes  through  all  the  field  coils  in 
the  motor  case,  one  after  another,  and  then  to  the  track 
by  way  of  the  axle  and  rails.  The  track,  as  we  know, 
forms  the  return  conductor  carrying  the  current  used 
by  all  the  cars  along  the  line  back  to  the  dynamo  in  the 
power  station,  thus  completing  the  circuit. 

Figure  91  is  a  diagram  of  the  wiring  in  a  car.  The 
two  controllers  are  represented  at  the  extreme  ends 
and  the  four  car  wheels  are  indicated  by  1,  2,  3  and  4; 
between  these  four  wheels  are  shown  the  outlines  of 


THE  MOTORMAN. 


CAR    WIRING    AND    PARTS.  89 

the  two  motors.  The  heavy  tube-like  connection  from 
the  controllers  to  the  motors  represents  a  hose  which 
surrounds  the  wires  going  to  each  motor.  It  protects 
them  partly  from  mechanical  injury  and  partly  from 
dampness  and  water  thrown  by  wheels  or  rails.  The 
resistance,  hose  and  other  devices  are  beneath  the  car- 
floor. 

Figure  92  is  a  diagram  of  the  wiring  of  the  type  of 
double-truck  car  used  by  the  Chicago  City  Railway.  It 
will  be  noted  that  this  car  has  four  motors  and  three 
main  groups  of  wires  or  cables  which  connect  the 
motors  and  the  resistances  with  the  controller. 

The  auxiliary  circuits  for  the  lights,  car  heaters, 
bells  and  air-compressor  motor  are  also  shown  in  de- 
tail in  Figures  93,  94  and  95. 

This  car  wiring  follows  the  practice  recently 
adopted  on  a  number  of  elevated  roads  of  putting  all 
wires  under  the  car  in  iron  pipe  conduit.  The  motor 
wires  between  controllers  are  bunched  into  three  cables. 
One  of  these  cables  contains  the  wires  for  motors  1  and 
2,  which  motors  are  placed  on  one  truck.  The  second 
cable  contains  wires  for  motors  3  and  4,  placed  on  the 
other  truck.  The  third  cable  contains  wires  going  to 
the  resistance  grids.  The  compressor  wiring  is  run 
in  separate  iron  pipe  conduit.  The  iron  pipe  conduit 
for  the  main  cables  runs  along  the  center  longitudinal 
sills  of  the  car.  The  accompanying  car  wiring  dia- 
gram indicates  these  cables  and  the  wires  leading  to 
them,  but  is  not  intended  to  show  the  position  of 
the  conduits.  Each  cable  conduit  has  all  its  wires  of 
different  color,  so  their  is  no  confusion  in  repairing. 

Where  the  taps  are  taken  off  from  the  cable  to  the 
motor  leads,  a  split  cast-iron  junction  box  containing 
the  joints  is  bolted  on  the  conduit.  These  taps  are  led 


90 


THE    MOTORMAN. 


i 


f 


I! 


f 


CAR    WIRING    AND    PARTS.  91 

to  a  connection  box,  which  is  intended  to  make  it  pos- 
sible to  quickly  disconnect  the  motor  leads  without 
the  inconvenience  of  disconnecting  joints  and  remov- 
ing joint  insulation. 


CHAPTER   VII. 


CONTROLLERS. 

For  controlling  the  speed  of  electric  cars  three 
general  methods  have  been  employed,  two  of  which, 
however,  are  practically  obsolete  today.  One  method 
is  by  means  of  a  rheostat,  which  was  the  system  intro- 
duced by  the  Thomson-Houston  Company.  In  this 
method  of  control  the  motors  were  connected  perma- 
nently in  parallel,  and  a  rheostat  was  inserted  in  series 
with  the  two  motors,  containing  sufficient  resistance 
to  reduce  the  starting  pressure  to  less  than  half  of  the 
total  voltage.  This  resistance  was  gradually  cut  out 
until  the  full  voltage  of  the  circuit  passed  through  the 
motors  as  the  car  reached  its  maximum  speed. 

Another  method  of  motor  control  no  longer  used 
for  street  cars  is  that  in  which  the  field  coils  are 
divided  into  several  sections,  the  sections  being  con- 
nected in  series  with  each  other  and  also  in  series  with 
the  armature  in  starting.  By  changing  in  successive 
steps  with  the  movement  of  the  controller  they  are  all 
thrown  in  parallel,  and  in  parallel  with  the  armature, 
when  the  car  attains  its  maximum  speed.  A  starting 
rheostat  is  also  used  with  this  method  of  control,  but 
it  is  in  series  only  on  the  first  notch  of  the  controller 
when  the  car  is  starting  from  rest.  Both  of  these  sys- 
tems are  now  practically  out  of  use. 


CONTROLLERS.  93 

The  series-parallel  method  of  control,  which  is  now 
universally  used,  and  which  has  supplanted  all  other 
methods,  consists  in  grouping  the  motors  on  the  car, 
together  with  the  starting  rheostat,  in  series  and  grad- 
ually, through  the  successive  steps  of  the  controller, 
changing  them  to  parallel  connection  when  the  car 
attains  its  greatest  speed.  A  number  of  controllers 
are  described  in  the  following  pages. 

The  car  controller  is  a  combination  of  switches 
adapted  to  control  the  speed  of  the  motors  by  admit- 
ting more  or  less  electrical  energy  to  the  motors  as 
the  case  may  require.  These  changes  of  connections 
may  be  made  by  a  number  of  independent  and  separate 
switches,  but  if  this  were  done  too  many  switches 
would  be  required,  and  they  would  be  slow  and  awk- 
ward to  operate,  and  would  occupy  too  much  room. 
Experience  has  shown  that  a  circular  contact  drum  is 
quick  acting  and  a  suitable  device  on  which  a  great 
many  changes  of  connections  can  be  made  simply  and 
easily.  The  purpose  of  the  controller  is  threefold  : 

1.  To  connect  the  motors  into  the  circuit  so  that 
current  can  flow  through  them. 

2.  To  regulate  the  amount  of  current  flowing  to 
the  motors  so  as  to  make  a  gradual  start  and  control 
the  speed  of  the  car. 

3.  To  govern  the  direction  of  travel  of  the  car. 

The  electrical  pressure  on  the  trolley  line  (techni- 
cally called  voltage)  is  kept  practically  constant  at  the 
power  station.  Therefore,  if  the  current  at  full  pressure 
were  admitted  suddenly  to  the  motors,  and  no  means 
provided  to  allow  it  to  rise  gradually,  we  would  have 
to  expect  a  similar  abrupt  and  sudden  start  by  the 
motors  from  a  state  of  rest.  Admitting  the  full  cur- 
rent would  strain  the  electrical  parts,  and  similarly  the 


94  THE    MOTORMAN. 

sudden  start  from  rest  to  high  speed  would  tax  the 
bearings  and  other  mechanical  supports  and  gears,  to 
say  nothing  of  the  discomfort  which  the  passengers 
would  experience  by  the  jerk  with  which  the  motors 
would  start  the  car. 

Resistance.  —  To  control  the  amount  of  current  it 
necessary   to    consume   a   portion   of  the   pressure 


is 


Figure  96 — Car  Resistance. 

under  which  the  current  flows  by  interposing  some 
material  which  offers  a  resistance  to  the  flow  of  the 
current  until  the  motor  has  been  gradually  increased  to 
its  normal  speed.  All  the  switches  or  contacts  for  such 
grading  or  varying  of  resistance  are  mounted  on  the 
drum  of  the  controller  (described  later),  while  the 
resistance  itself  is  generally  fixed  at  a  convenient  place 
below  the  car  body.  Substances  that  offer  resistance 
to  the  flow  of  current  are  iron  wire,  iron  strips  or 
plates,  German  silver,  etc.  For  electric  railway  pur- 


CONTROLLERS. 


poses  iron  plates  or  bands  are  generally  used,  which 
are  supported  in  an  iron  frame,  the  turns  or  convolu- 
tions being  insulated  from  each  other  and  the  fireproof 
frame  by  mica.  The  complete  device  is  termed  a  re- 
sistance, though  some  call  it  a  rheostat  or  a  diverter. 

Assume,  for  the  sake  of  illustration,  that  the  total 
length    of    the  iron    resistance    band  is    40    feet,   in 
divisions  of  10  feet  each,  these  divisions  being  con- 
nected to  the  controller 
terminals  by  means  of 
wires  mentioned  in  the 
previous  chapter.   Now, 
if  this  controller  were 
placed  on  the  first  notch 
the  whole  40  feet  of  iron 
band  would  be  in  circuit 
with  the  motor,  and  the 
pressure      that      could 
reach     the     motor     re- 
duced just  the  amount 
that   would   be   lost  in 
By    turning    the    con- 
10    feet    of    this    iron 


Figure  97 — Resistance  Grid. 


so    that    but    30    feet 


the  40  feet  of  iron  band, 
troller  to  the  second  notch, 
band  would  be  cut  out, 
would  be  in  circuit.  The  pressure  that  could  reach 
the  motor  in  this  case  would,  of  course,  be  greater  and 
its  speed  would  increase.  Turning  the  controller  to 
the  third  notch,  but  20  feet,  to  the  fourth  notch,  but 
10  feet,  of  the  resistance  would  be  left  in  the  circuit, 
and  at  the  fifth  position  the  resistance  would  be  out 
entirely,  causing  an  increase  of  speed  with  every  re- 
duction in  resistance  and  a  maximum  speed  when  all 
resistance  was  cut  out.  A  resistance  or  diverter  is 
shown  in  Figure  96.  Its  terminals,  by  which,  as  just 


96  THE    MOTORMAN. 

explained,  the  resistance  is  subdivided  (Figure  97),  are 
led  to  the  controller. 

Motor  Circuits.— In  order  to  understand  clearly 
all  the  different  changes  and  conditions  that  take  place 
by  means  of  the  controllers,  it  is  desirable  to  make 
the  reader  acquainted  first  with  the  different  modes 
of  circuit  connection  and  their  names,  and  then  imme- 
diately apply  them  to  standard  types  of  controllers. 
After  the  preliminary  explanation  some  types  in  gen- 


Figure  98. 


Figure  99. 


eral  use  will  be  described  in  detail,  and  the  rest  will  be 
understood  after  a  simple  statement  of  the  successive 
steps  and  changes  as  they  take  place. 

If  several  parts  or  conductors  are  grouped  so  that 
the  total  current  flows  in  succession  through  all  parts, 
they  are  said  to  be  grouped  in  ' '  series, ' '  as  for  instance 
in  Figure  98.  The  trolley,  the  main  fuse  and  the  re- 
sistance carry  the  total  current  that  goes  to  the  motors, 
and  they  are  said,  or  each  one  of  them  is  said,  to  be 
in  series  with  the  motors.  The  motors  are  also  in  series 
with  each  other,  as  the  current  flows  first  through  one, 
then  through  the  other.  It  will  be  clear  that  if  for 
any  cause  the  main  fuse  should  melt,  there  would  be  a 


CONTROLLERS.  97 

separation  between  the  trolley  pole  and  the  resistance 
and  the  current  could  not  flow. 

Another  mode  of  connection  is  called  "parallel" 
or  ''multiple"  connection.  This  is  shown  in  Figure 
99.  The  full  current  supplied  to  a  car  goes  down  the 
trolley  pole,  and  if  the  motors  are  grouped,  as  shown  in- 
this  figure,  the  current  will  divide  and  half  of  it  will 
go  to  one  motor  and  the  other  half  to  the  other  motor. 
Where  the  circuits  of  the  motors  are  connected  again 
the  two  currents  join  and  flow  on  as  one  through  the 
car  wheel  and  rail.  The  two  motors  are  connected  in 
parallel  or  multiple  with  each  other.  Hov/ever,  this 


Figure  100. 

connection  is  not  restricted  to  motors  only.  Any  two 
or  more  conductors  placed  in  such  a  relation  that  the 
original  current  will  split  up  into  several  paths  and 
join  at  a  place  farther  on  are  said  to  be  connected  in 
parallel,  or  shunt,  or  in  multiple.  For  instance,  re- 
sistance may  be  in  parallel  with  or  in  shunt  circuit  to 
the  field  coils  of  a  motor  (Figure  100),  a  connection 
which  is  made  in  some  modern  controllers. 

A  third  way  of  connecting  parts  is  made  by  a 
combination  of  the  two  ways  just  described.  Some 
of  the  devices  with  relation  to  others  are  in  series  with 
one  another  and  in  parallel  with  others,  and  such 
grouping  is  called  series-parallel  or  parallel-series 
connection.  Figure  101  explains  this  clearly.  It  rep- 
resents a  condition  of  grouping  of  four  motors,  1,  2,  3 
and  4. 


98  THE    MOTORMAN. 

Evidently  the  current  splits  at  A,  divides  into 
two  currents,  one  of  which  flows  through  motors  1  and 
2,  the  other  through  motors  3  and  4.  The  volume  of 
current  that  goes  through  motor  2  must  therefore  be 
the  same  as  that  going  through  motor  1,  and  the  rela- 
tion is  similar  between  motors  3  and  4.  At  point  B 
the  currents  join  and  the  total  current  flows  to  the  car 
axle  and  car  wheel  C.  In  this  combination  motors  1 
and  2  are  in  series,  and  so  are  motors  3  and  4,  but  the 
1  and  2  combined  are  in  parallel  connection  with  3  and 


Figure  101. 

4  combined,  and  the  whole  combination  is  called  series- 
parallel. 

Series-Parallel  Control. — Since  1893  an  improved 
form  of  controller  known  as  the  "series-parallel"  con- 
troller, has  come  into  general  use  for  single-car  opera- 
tion. The  power  required  when  first  starting  a  car 
with  the  motors  in  series  is  only  one-fourth  what  it 
would  be  with  the  same  motors  in  parallel.  Conse- 
quently, in  the  modern  controller  the  motors  are  in 
series  on  the  first  few  points  of  the  controller  as  in 
Figure  98,  and  after  about  half  speed  has  been  reached 
they  are  connected  in  parallel  as  in  Figure  99.  Hence 
the  name,  series-parallel  controller. 

The  difference  between  the  old  method  of  control 
and  the  new  is  that  formerly,  to  reduce  the  pressure 


CONTROLLERS.  99 

at  the  motor  terminals  at  the  start,  a  great  resistance 
was  inserted  to  consume  a  part  of  the  pressure  and  the 
energy  thus  spent  in  the  resistance  was  wasted.  In 
the  new  way  the  two  motors  are  grouped  in  series  first, 
so  that  the  current  must  flow  through  one  motor  before 
it  gets  to  the  next  (Figure  98),  and  therefore  but  one- 
half  the  pressure  reaches  each  motor.  The  energy 
passing  through  the  first  motor  (which  causes  the  re- 
duction in  pressure  for  the  other)  is  not  wasted,  as  it 
is  doing  useful  work  in  turning  the  armature  and  in- 
creasing the  turning  force  necessary  for  starting  the 
car. 

Practically  all  new  cylindrical  controllers  in  use 
today  may  be  divided  into  four  classes,  as  follows : 

Type  B  controllers,  which  may  be  either  of  the 
series-parallel  or  rheostatic  type,  but  which  always  in- 
clude the  necessary  contacts  and  connections  for  oper- 
ating electric  brakes. 

Type  K  controllers  of  the  series-parallel  type  are 
almost  universally  used.  In  these  controllers  one  of 
the  features  is  the  shunting  or  short  circuiting  of  one 
of  the  motors  when  changing  from  the  series  to  the 
parallel  connection. 

Type  L  controllers  are  also  of  the  series-parallel 
type,  but  differ  from  type  K  controllers  in  that  the 
circuit  is  completely  opened  when  the  change  from 
series  to  parallel  is  made. 

One  of  the  most  important  features  of  these  types 
of  controllers  is  the  magnetic  blow-out  by  means  of 
which  any  arc  forming  between  the  controller  ter- 
minals is  blown  out.  Other  important  features  are  the 
cut-out  switches  and  the  interlocks.  The  cut-out 
switches  are  arranged  so  that  either  motor  on  the  two- 
motor  equipments,  or  either  pair  of  motors  on  the  four- 


100  THE    MOTORMAX. 

motor  equipments,  may  be  cut  out  without  impairing 
the  operation  of  the  remaining  motors.  The  interlocks 
prevent,  as  far  as  possible,  the  abuse  of  the  controller, 
as  they  make  movement  of  any  of  the  handles  impossi- 
ble unless  the  remaining  handles  are  in  such  a  position 
that  no  trouble  can  result.  These  controllers  are 
built  with  hinge  clamps,  permitting  the  cover  to  swing 
open  from  either  side,  or  to  be  completely  removed. 
The  parts  of  all  these  controllers  are  interchangeable, 
permitting  ease  of  repair  and  renewal. 

In  the  following  descriptions  of  controllers  there 
are  included  controllers  which  are  no  longer  manu- 
factured, but  many  of  these  older  controllers  are  still 
to  be  found  on  different  roads  where  the  old  equip- 
ments have  not  yet  been  discarded,  and  it  was  there- 
fore deemed  advisable  to  include  descriptions  of  the  old 
as  well  as  the  modern  controllers. 

The  series-parallel  controllers  manufactured  at  the 
present  time  are  as  follows :  K-2,  capacity  two  40-hp. 
motors,  5  series  and  4  parallel  points;  K-4,  capacity 
four  30-hp.  motors,  5  series  and  4  parallel  points ;  K-6, 
two  80-hp.  or  four  40-hp.  motors,  6  series  and  5  paral- 
lel points;  K-10,  two  40-hp.  motors,  5  series,  4  parallel 
points;  K-ll,  two  60-hp.  motors,  5  series  and  4  parallel 
points;  K-12,  four  30-hp.  motors.  5  series  and  4  parallel 
points;  K-13,  two  125-hp.  motors,  7  series,  6  parallel 
points;  K-14,  four  60-hp.  motors,  7  series,  6  parallel 
points;  K-27,  two  60-hp.  motors,  4  series,  4  parallel 
points;  K-29,  four  40-hp.  motors,  6  series  and  5  parallel 
points;  K-31,  four  30-hp.  motors,  4  series  and  4  parallel 
points;  K-32,  twro  40-hp.  motors,  4  series  and  4  parallel 
points;  L-2,  two  175-hp.  motors,  4  series  and  4  parallel 
points ;  L-3,  four  150-hp.  motors,  8  series  and  7  parallel 
points;  L-4,  four  100-hp.  motors,  4  series,  4  parallel 


CONTROLLERS.  101 

points;  L-7,  four  200-hp.  motors,  9  series  and  6  parallel 
points. 

The  electrical  brake  controllers  are  designated  by 
the  letter  B,  and  are  as  follows : 

B-3,  capacity  two  40-hp.  motors,  4  series,  5  parallel 
and  6  brake  points;  B-7,  two  100-hp.  motors,  6  series> 

5  parallel  and  6  brake  points;  B-8,  four  60-hp.  motors, 

6  series,  5  parallel  and  7  brake  points ;  B-13,  two  40-hp. 
motors,  5  series,  4  parallel  and  7  brake  points;  B-18, 
two  40-hp.  motors,  4  series,  4  parallel  and  6  brake 
points;  B-19,  four  40-hp.  motors,  5  series,  4  p&rallel,  7 
brake  points ;  B-23,  two  60-hp.  motors,  5  series,  4  paral- 
lel and  7  brake  points ;  B-29,  two  60-hp.  motors,  5  series, 
4  parallel  and  7  brake  points.     The  latter  is  similar  to 
B-23,  but  has  a  separate  brake  handle. 

In  Figure  102  is  shown  one  of  the  type  K  con- 
trollers of  the  General  Electric  Company.  There  are 
many  types  of  K  control  adapted  for  motors  of  differ- 
ent ratings,  but  the  principle  of  operation  of  all  is 
similar,  so  one  description  will  suffice.  On  the  top  of 
the  controller  are  visible  two  handles.  The  one  located 
near  the  center  of  the  controller  top,  called  the  con- 
troller handle,  is  attached  to  a  spindle  which  passes 
through  the  whole  length  of  the  controller.  On  this 
spindle  is  mounted  a  cylinder  by  means  of  which  the 
current  is  turned  into  the  motors.  The  second  han- 
dle, called  the  reversing  handle,  is  located  at  the 
right-hand  side  and  its  purpose  is  to  control  the  direc- 
tion of  the  car.  If  this  handle  is  pushed  forward 'as 
far  as  it  will  go,  the  car  will  go  ahead  when  the  con- 
troller handle  is  turned  to  close  the  circuit.  The  car 
will  run  backward  when  the  reversing  handle  has  been 
pulled  to  the  other  extreme  position  and  the  controller 
handle  is  operated  as  before.  What  takes  place  is  this : 


102  THE    MOTORMAN. 

The  reversing  lever  operates  a  small  drum  inside  of 
the  controller  which  is  provided  with  contacts.  This 
handle  has  three  positions.  The  working  of  this  handle 
forward  or  backward  changes  the  connections  of  the 


Figure  102—  K-2  Controller. 

motor  armatures  so  that  the  current  flows  through 
them  in  one  direction  when  the  car  is  to  go  ahead,  and 
in  the  opposite  direction  when  the  car  is  to  go  back- 
ward, as  explained  in  the  previous  chapter.  When 
the  reverse  handle  stands  at  the  intermediate  position 


CONTROLLERS.  103 

between  forward  and  reverse,  the  current  is  shut  off 
from  the  motor  at  that  controller  and  the  reversing 
handle  can  be  removed  only  when  it  is  at  this  interme- 
diate position.  An  interlocking  arrangement  pre- 
vents any  movement  of  the  reversing  handle  except 
when  the  large  or  power  cylinder  is  at  the  "off"  posi- 
tion. This  same  locking  device  prevents  any  movement 
of  the  power  cylinder  except  when  the  reversing  han- 
dle is  fully  thrown  into  proper  position  and  standing 
At  either  "forward"  or  "backward." 

The  reversing  cylinder,  therefore,  controls  the  di- 
rection in  which  the  car  moves.  The  propelling  of  the 
car  and  its  speed  are  controlled  by  the  controller  handle, 
with  which  the  motorman  has  far  more  to  do  than  with 
the  one  just  described.  We  will,  therefore,  go  fully 
into  the  details  of  changes  that  take  place  when  the 
controller  handle  is  shifted  from  one  point  to  another. 

On  the  top  of  the  controller  there  are  a  number 
of  points  or  dashes,  and  on  the  spindle  is  fastened  a 
finger  or  index  which  points  to  these  raised  marks  as 
the  handle  is  moved  around  to  admit  current  to  the 
motors.  The  high  controlling  lever  on  the  top  (Figure 
102)  turns  the  central  shaft  on  which  are  mounted  the 
contact  pieces  or  sections,  which  establish  connections 
with  the  stationary  terminals  located  to  the  left.  The 
wires  to  the  left  connect  with  the  terminal  board  in  the 
controller,  to  which  are  also  attached  the  wires  going  to 
the  motors  and  to  the  second  controller  and  resistance 
boxes. 

When  the  car  is  standing  ready  to  start,  the  finger 
points  to  the  position  marked  "off."  To  start  the  car, 
the  handle  is  moved  around  in  the  direction  of  the 
hands  of  a  watch  to  the  first  point.  This  connects  the 
motors  and  resistance  to  the  circuit  so  that  the  current 


104  THE    MOTORMAN. 

ftes/s/a/?ce     Sf0for/fo.f        Mofor/Vo.2 


^^Jw\/^ 
^^^ 

J^ 


\ 

Figure   103 — Motor  Connection?  on  Successive   Point*. 


CONTROLLERS.  105 

flows  first  through  the  iron  plates  of  the  resistance, 
then  through  one  of  the  motors,  then  through  the  other 
motor,  and  finally  to  the  ground  through  the  car  truck, 
wheels  and  rails.  The  motors  are  in  this  case  what  is 
technically  known  as  connected  in  "series."  This  is 
represented  in  the  diagram  showing  the  connections  on 
the  first  point  in  Figure  103.  The  connections  made  on 
all  the  following  points  of  this  controller  are  also 
shown  in  the  same  figure  and  should  be  studied  while 
reading  this  explanation.  On  the  second  point  it  will 
be  seen  that  the  connections  remain  the  same  as  on  the 
first,  except  that  two-thirds  of  the  resistance  has  been 
cut  out  of  the  circuit,  so  that  more  current  may  reach 
the  motors.  On  the  third  point,  eleven-twelfths  of  the 
resistance  is  cut  out  of  the  circuit,  and  on  the  fourth 
point,  all  the  resistance  is  out,  so  that  the  current 
flows  only  through  the  two  motors  in  series. 

All  resistance  is  now  cut  out  and  no  power 
is  being  wasted,  as  the  current  is  doing  only  useful 
work  in  the  motors.  We  can  therefore  keep  the  con- 
troller on  this  point  for  any  length  of  time  with  econ- 
omy, only  the  car  will  run  a  little  less  than  half  its 
maximum  speed.  To  increase  the  speed  still  more,  we 
move  the  controller  to  the  fifth  point.  In  doing  this, 
connections  are  made  so  that  part  of  the  current  is 
shunted  through  a  resistance  around  the  field  coils  of 
the  motor;  that  is,  instead  of  having  all  the  current 
that  flows  through  the  armatures  flow  also  through 
the  fields,  a  part  of  it  is  made  to  take  a  by-pass  or 
shunt  around  the  fields.  This  has  the  effect  of  increas- 
ing the  speed  of  the  motors,  and  they  will  on  this  point 
run  at  half  the  full  speed.  In  moving  the  controller 
to  the  sixth  point,  an  important  change  is  made  in  the 
connections  of  the  motors. 


106  THE    MOTORMAN. 

As  said  before,  when  the  controller  is  on  the  fourth 
and  fifth  points,  the  motors  are  in  series  with  each 
other,  the  current  flowing  first  through  one  and  then 
through  the  other.  Consequently  each  motor  gets  only 
one-half  the  pressure  existing  between  the  trolley 
wire  and  ground.  That  is  to  say,  by  the  time  the  cur- 
rent has  passed  through  the  first  motor,  half  of  the 
pressure  has  been  used,  leaving  only  the  remaining 
half  to  run  the  other  motor.  To  increase  the  speed  we 
must  now  connect  the  motors  so  that  they  both  will 
get  the  full  pressure  from  the  trolley  line.  This  can- 
not be  done  abruptly.  Some  resistance  must  be  intro- 
duced into  the  circuit  at  the  time  this  change  is  made 
to  prevent  the  car  from  jerking,  just  as  it  would  have 
acted  on  the  first  point  had  some  resistance  not  been 
interposed  when  first  starting.  Therefore,  on  the  sixth 
point,  the  motors  are  connected  so  that  the  current  di- 
vides and  half  flows  through  each  motor.  They  arc 
then  what  is  technically  called  connected  in  "parallel." 
They  both  get  the  full  pressure,  except  that  some  re- 
sistance is  put  in  the  circuit  before  the  current  gets  to 
the  motors.  A  part  of  this  resistance  is  cut  out  on  the 
seventh  point.  On  the  eighth  point  all  of  the  resist- 
ance is  out  and  the  motors  are  connected  so  that  they 
both  get  the  full  pressure  and  run  at  nearly  full  speed. 
On  the  ninth  point  part  of  the  current  is  shunted 
around  the  field  coils  as  on  the  fifth  point,  and  the  mo- 
tors run  at  their  highest  speed. 

At  each  point  there  is  provided  a  notch  on  a  wheel 
or  ratchet,  mounted  on  the  controller  spindle  inside 
the  controller  case,  which  prevents  the  handle  from 
stopping  between  points  when  it  is  turned.  At  the 
lower  end  of  the  controller  are  located  the  motor  cut- 
out switches,  which  enable  one  to  operate  a  car  with  a 


CONTROLLERS. 


107 


single  motor  should  the  other  one  have  become  de- 
fective. The  operator  will  find  an  instruction  card  in 
each  controller,  stating  plainly  how  to  throw  the 
switches  to  cut  out  the  defective  motor.  It  will  be 


Figure   104— K-6   Controller. 


noticed  that  the  cards  do  not  read  alike  on  the  two 
controllers  of  the  same  car.  This  is  due  to  the  differ- 
ence in  connection.  Should  it  at  any  time  become 
necessary  to  cut  out  a  motor,  look  for  the  instruction 


108  THE    MOTORMAN. 

card  in  the  controller  stand.  To  operate  with  a  single 
motor,  the  car  will  start  on  point  1  and  reach  its  full 
speed  on  point  5.  A  stop  is  placed  on  the  controller 
spindle,  with  which  a  pin  engages,  preventing  move- 
ment of  the  controller  cylinder  beyond  the  fifth  point. 
This  is  effected  by  either  of  these  cut-out  switches, 
which,  in  being  raised,  operate  the  pin. 

The  K-4  controller  is  used  in  connection  with 
larger  cars,  where  four  motors  instead  of  two  are 
mounted  on  the  trucks.  Its  action  is  like  the  K-2  con- 
troller, with  the  difference  that  instead  of  having  two 
motors  first  in  series  and  later  in  parallel,  there  are  in 
the  K-4  control  two  identical  sets  of  motors  with  two 
motors  per  set.  The  two  motors  of  each  set  are  perma- 
nently grouped  in  parallel,  and  one  pair  is  first  placed 
in  series  with  the  other  pair  or  set.  and  finally  the  two 
series  are  connected  in  parallel. 

The  K-6  controller,  which  is  designed  for  two  80- 
hp.  motors  or  four  40-hp.  motors,  is  shown  in  Figure 
104. 

The  K-10  controller  is  designed  for  two  40-hp. 
motors.  It  is  a  controller  with  nine  notches.  On  the 
first  four  notches  the  motors  are  in  series  and  the  re- 
sistance in  circuit.  On  the  fifth  notch  the  motors  are 
in  series  with  the  resistance  all  cut  out.  On  the  sixth, 
seventh  and  eighth,  the  motors  are  in  parallel  and  the 
resistance  in  circuit.  The  ninth  is  for  full  speed,  mo- 
tors in  multiple.  The  K-10  controller  is  shown  in  Fig- 
ure 105.  Field  shunts  are  not  used  with  this  controller. 

The  K-ll  controller  is  the  same  as  the  K-10,  except 
it  is  designed  for  heavier  currents  and  larger  motors. 

The  K-12  controller  is  like  the  K-ll,  except  that  it 
is  made  to  operate  four  motors  in  two  sets,  the  same 
as  the  K-4. 


CONTROLLERS.  109 

The  K-13  is  designed  for  two  125-hp.  motors.  It 
is  a  13-notch  controller.  The  motors  are  in  series  up 
to  and  on  the  seventh  point.  From  the  eighth  to  the 


Figure  105—  K-10   Controller. 

thirteenth  they  are  in  multiple.  The  preferred  running 
notches  are  the  seventh  and  thirteenth.  No  field  shunts 
are  used. 

The  K-14  is  for  four  60-hp.  motors,  and  is  like  the 


110  THE    MOTORMAN. 

K-13,  except  that  it  bandies  four  motors  in  two  groups, 
as  does  the  K-4. 

The  K-27  controller  is  similar  to  the  K-ll,  but  is 
arranged  for  operation  on  a  metallic  circuit,  having 
contacts  for  opening  both  sides  of  the  circuit. 

The  K-29  controller  is  similar  to  the  K-6,  but  has 
contacts  for  opening  both  sides  of  the  circuit. 

The  K-31  controller  is  similar  to  the  K-27,  but  has 
reverse  switch  arranged  for  four  motors. 

The  K-32  controller  is  also  similar  to  the  K-27,  but 
is  of  smaller  capacity. 

The  L-2  controller  is  used  for  two  175-hp.  motors, 
and  the  L-4  for  fou:.'  100-hp.  motors.  They  have  four 
points  in  series  and  four  in  multiple.  The  handle  is 
operated  contrary  to  the  hands  of  a  watch,  or  in  the 
opposite  direction  from  most  controllers.  The  first 
half-revolution  moves  the  controller  through  the  series 
points  and  brings  them  into  full  series.  To  throw 
them  into  multiple  the  movement  of  the  handle  of  the 
controller  is  continued  on  around  to  the  original  off 
position,  and  when  the  handle  begins  to  pass  over  what 
were  the  series  notches  on  the  first  revolution,  the 
motors  are  thrown  in  multiple,  so  that  when  the  handle 
has  completed  a  revolution  and  a  half  the  motors  are 
connected  for  full  speed  in  multiple.  The  current  is 
always  off  when  the  handle  is  at  the  left,  and  always 
on  when  it  is  at  the  right.  A  brass  dial  on  top  of  the 
controller  indicates  whether  the  motors  are  in  series 
or  multiple. 

The  L-3  controller  for  four  150-hp.  motors  has  15 
points,  eight  series  and  seven  parallel.  This  controller 
is  shown  in  Figure  106. 

The  L-7  controller  for  four  200-hp.  motors  has  15 
points,  nine  series  and  six  parallel. 


CONTROLLERS?  Ill 

The  controllers  for  use  with  electric  brakes  are 
known  as  the  B  type.  The  action  of  the  electric  brake 
and  the  way  to  operate  it  are  described  later  in  the 
chapter  on  brakes.  Some  of  these  controllers  have  a 
double  set  of  points  or  notches.  Moving  the  handle 


Figure    106 — L-3   Controller. 

in  the  usual  way  from  off  position  starts  the  car  just 
as  on  other  controllers.  Moving  the  handle  the  other 
way  from  off  position  applies  the  electric  brake,  if  the 
car  is  running.  The  capacities  of  the  B  controllers  at 
present  manufactured  and  the  number  of  controlling 
points  on  each  have  already  been  shown  in  this  chapter. 


112 


THE    MOTORMAN. 


The  B-8  controller  has  separate  handles  for  power  and 
brake,  as  is  also  the  case  with  the  B-7,  B-19  and  the 
B-29. 

The  B-23  controller  has  but  one  power  and  brake 
handle.  The  B-3,  B-13  (shown  in  Figure  107)  and  B-18 
also  have  only  one  handle,  which  is  operated  in  one 


Figure  107— B-13  Controller. 

direction  for  the  power  and  in  the  other  direction  for 
the  brake,  as  just  described.  Of  the  B  controllers  the 
B-13  is  most  generally  used  and  its  braking  connections 
are  such  as  to  render  the  skidding  of  the  wheels  prac- 
tically impossible. 

Controller  with  Contactors. — The  increased  power 
and  higher  voltages  now  being  used  on  many  electric 


CONTROLLERS. 


113 


railways  have  imposed  new  requirements  in  the  design 
of  control  apparatus  for  railway  motors,  mainly  owing 
to  the  more  destructive  character  of  the  arcing  in  case 
of  a  grounded  motor  or  derangement  of  other  appa- 


Figure   108— K-28-J   Controller. 


ratus.  To  meet  these  requirements  there  has  been  de- 
veloped an  auxiliary  equipment  adapted  for  use  with 
practically  all  standard  cylinder  controllers,  consisting 
essentially  of  two  standard  Sprague-General  Electric 
Type  M  control  contactors  (see  Chapter  VIII)  con- 


114 


THE    MOTORMAN. 


nected  in  the  main  trolley  circuit,  and  additional  con- 
tacts in  the  controllers  for  opening  and  closing  the 
contactors  when  the  controller  is  turned  off  and  on, 
respectively. 

By  this  means  all  heavy  arcing  is  eliminated  from 
the  controller  as  the  power  circuit  is  opened  by  the 
contactors  under  the 
car,  and  consequently 
the  wear  and  tear  on 
the  controller  fingers 
and  contact  surfaces  is 
diminished,  repairs  min- 
imized, and  the  possibil- 
ity of  burnt-out  control- 
lers practically  prevent- 
ed. A  controller  Type 
K-28-J  fitted  with  the 
contactor  attachments  is  Figure  109. 

shown  in  Figure  108. 

In  addition,  this  equipment  includes  overload  de- 
vices known  as  MU  tripping  switches  which  interrupt 
the  energizing  circuit  of  the  contactor  coils  in  case  of 
an  overload,  causing  the  contactors  to  open  the  main 
circuit.  These  tripping  switches  perform  the  functions 
of  circuit-breakers  and  may  be  substituted  for  them. 

The  control  connections  are  shown  in  the  wiring 
diagram  (Figure  109).  The  auxiliary  controller  at- 
tachments can  be  fitted  to  the  following  controllers: 
K-6,  K-10,  K-ll,  K-12,  K-14,  K-28  and  L-4,  with  but 
slight  change.  The  automatic  MU  tripping  switch  re- 
places the  usual  platform  circuit-breaker  and  is  smaller 


CONTROLLERS.  115 

and  more  compact.  This  combination  control  is  de- 
signed for  a  single-car  equipment  and  must  not  be  con- 
fused with  the  standard  multiple-unit  control  for  op- 
erating several  motor  cars  together,  which  is  described 
in  Chapter  VIII. 


CHAPTER   VIII. 


MULTIPLE-UNIT    CONTROL. 

On  some  electric  railways  where  the  traffic  is  heavy 
it  becomes  necessary  to  run  trains  of  several  ears, 
some  or  all  of  which  are  motor  cars.  It  also  becomes 
necessary  at  times  to  divide  these  trains  into  smaller 
ones  or  to  add  more  cars  as  the  traffic  fluctuates,  and 
as  it  is  obviously  unpractical  to  have  more  than  one 
motorman  to  drive  a  train,  means  must  be  provided  so 
that  each  motor  car  of  the  train  may  be  controlled  from 
the  head  end  by  one  man.  This  method  of  control  is 
generally  known  as  the  multiple-unit  system  of  control. 

The  multiple-unit  control  system  is  designed  to  op- 
erate a  train  of  two  or  more  cars  from  a  single  master 
controller  or  from  any  car  in  the  train.  The  train  con- 
sists of  several  cars,  each  propelled  independently  by  its 
own  motors  and  controlled  as  one  car.  Each  motor  car 
is  provided  with  two  master  controllers,  one  at  each  end 
of  the  car  in  the  motorman 's  compartment.  All  master 
controllers  are  connected  to  the  train  cable,  which  runs 
the  entire  length  of  each  car  and  is  joined  between  cars 
by  the  train  cable-jumper.  The  current  received 
through  the  master  controller  and  train  cable  operates 


MULTIPLE-UNIT    CONTROL.  117 

electrically  controlled  switches,  known  as  contactors,  on 
each  car,  and  establishes  the  motor  control  on  their 
respective  cars.  The  motor  control  is  local  with  each 
car  and  can  be  governed  by  any  master  controller  on 
the  train.  The  multiple-unit  system  allows  the  great- 
est flexibility  in  the  operation  of  cars,  for  one  car 
may  be  run  alone  or  any  number  of  cars  may  be  coupled 
together,  each  car  being  driven  by  its  own  motors  as  an 
independent  unit. 

There  are  two  systems  of  multiple  control  in  use, 
that  of  the  General  Electric  Company,  known  as  the 
type  M  control,  which  is  electrically  operated,  and  the 
Westinghouse  multiple-control  system,  which  is  oper- 
ated by  means  of  compressed  air,  and  known  as  electro- 
pneumatic  control.  Each  may  be  arranged  for  alter- 
nating-current service  as  well  as  direct. 

Type  M  Control.— In  the  type  M  control  the  series- 
parallel  motor  controller  as  described  in  the  previous 
chapter  is  replaced  by  a  number  of  electrically  oper- 
ated switches,  called  contactors,  which  are  placed  under 
each  motor  car.  There  is  also  a  separate  electrically 
operated  reversing  switch  called  the  reverser.  These 
contactors  and  the  reverser  fulfill  the  same  functions 
as  the  controllers  on  a  single  car,  making  the  same 
combination  of  the  motors  and  starting  resistances. 
Instead,  however,  of  being  directly  operated  by  the 
motorman  they  are  operated  through  a  small  controller, 
called  the  master  controller,  to  which  all  the  con- 
tactors and  reversers  on  the  train  are  attached  by 
means  of  a  control  circuit  cable.  This  cable  runs  the 
entire  length  of  the  train  and  is  connected  from 
car  to  car  by  means  of  suitable  couplers,  and  when 
trail  cars  are  placed  between  motor  cars  they  also  are 
provided  with  cables.  The  platforms  of  each  motor 


118 


THE    MOTORMAN. 


car  and,  if  desired,  those  of  each  trail  car  are  equipped 
with  master  controllers  (Figure  110). 

The  master  controller,  type  C-38-D,  shown  in  Fig- 
ure 111,  although  smaller  than  the  ordinary  controller, 
is  similar  in  appearance  and  method  of  operation.  It 
has  separate  power  and  re- 
verse handles  and  contains 
a  magnetic  blowout  simi- 
lar to  that  of  the  ordinary 
controller.  All  the  current 
for  the  operation  of  the 
contactors  is  taken  from 
the  line  and  passes  direct- 
ly through  whichever  mas- 
ter controller  happens  to 
be  in  use ;  and  the  handle 
of  the  master  controller  is 
generally  arranged  so  that 
if  the  motorman  removes 
his  hand  from  it  the  con- 
trol circuit  will  be  broken 
and  the  contactors  opened, 
shutting  off  all  current 
from  the  motors.  The  re- 
verse handle  can  only  be 
removed  when  the  power 

handle  is  in  the  off  posi-    Controller  ^witches  m  cab. 
tion  and  the  power  handle 

is   mechanically   locked   when   the    reverse   handle    is 
removed. 

The  contactors  (Figures  112  and  113)  each  con- 
sist of  a  movable  arm  with  a  removable  copper  con- 
tact at  one  end,  making  contact  with  a  similar  fixed 
contact  piece,  and  a  coil  which  actuates  the  arm  when 


MULTIPLE-UNIT    CONTROL. 


119 


Figure  111— C-38-D  Controller. 


120 


THE    MOTORMAN. 


MULTIPLE-UNIT    CONTROL.  121 

supplied  with  current  from  the  master  controller.  The 
contactor  is  closed  only  when  the  current  of  the  con- 
trol circuit  passes  through  its  coil,  and  gravity,  as- 
sisted by  the  spring  action  of  the  contact  piece,  causes 
the  arm  to  drop  and  the  circuit  to  open  when  the  con- 
trol circuit  is  broken.  The  contactor  also  has  a  pow- 
erful magnetic  blow-out.  The  reverser  is  somewhat 
similar  to  the  ordinary  reversing  switch  with  the  addi- 
tion of  electro-magnets  for  turning  it  either  to  the 
forward  or  reverse  positions.  Its  operating  coils  are 
similar  to  those  of  the  contactors.  A  cut-out  switch  is 
also  provided,  by  means  of  which  all  of  the  control  op- 
erating circuits  on  any  car  may  be  cut  out. 

It  is  evident  from  the  foregoing  explanation  that 
there  are  two  principal  circuits  (Figure  114  at  end  of 
book)  on  a  car  with  the  type  M  control.  First,  the  con- 
trol circuit  which  passes  from  the  line  to  the  contact 
shoe  on  the  car,  thence  to  the  master  controller,  thence 
through  the  various  operating  coils  of  the  contactors 
and  reverses  and  thence  to  the  ground  return;  second, 
the  motor  circuit,  which  from  the  contact  shoe  passes 
through  the  various  contactors,  thence  to  the  motor 
fields  and  armatures  and  thence  to  the  ground  return. 
All  of  the  contactors  under  each  car  taken  together 
constitute  a  series-parallel  controller,  and  the  different 
combinations  are  indicated  by  the  position  of  the  mas- 
ter controller  handle.  The  diagram  (Figure  116  at  end 
of  book)  shows  the  complete  connections  of  the  C-36-B 
controller  and  its  auxiliary  apparatus  for  a  four- 
motor  equipment.  The  running  points  on  this  con- 
troller are  5  and  10,  5  being  the  series  connection  of 
the  motors  and  10  the  parallel  connection.  The  inter- 
mediate points  are  resistance  points.  As  this  system  of 
control  is  made  up  of  separate  electrically  operated 


122 


THE    MOTORMAN. 


switches,  these  may  be  located  in  any  available  posi- 
tion and  are  generally  placed  under  the  car  floor. 

Electro-Pneumatic  Control. — The  Westinghouse 
multiple  unit-switch  train  control  system  employs  com- 
pressed air  to  operate  the  controlling  apparatus,  elec- 
tro-magnetic valves  for  controlling  the  admission  of  air 
to  the  various  cylinders  and  a 
low-voltage  control  circuit  for 
actuating  the  electro-magnets. 
The  essential  parts  of  this  sys- 
tem consist  of  a  series-parallel 
controller  on  which  is  mounted 
an  operating  head  consisting  of 
a  number  of  air  cylinders,  a 
master  control  switch  and  two 
sets  of  storage  batteries.  With 
some  changes  the  system  is 
adapted  for  either  alternating 
or  direct  current  operation. 

In  the  unit-switch  control 
system  the  main  drum  of  the 
hand  controller  is  replaced  by 
a  group  of  10  or  12  (according 
to  the  size  of  the  equipment) 
Independent  or  "unit"  switches, 
each  provided  with  a  strong 
magnetic  blow-out  and  normally 

held  open  by  a  powerful  spring.  Each  switch 
(Figure  115)  is  closed  when  desired  by  a  suit- 
able pneumatic  cylinder,  using  compressed  air  from 
the  brake  system.  This  combination  of  switches  is 
called  a  "switch  group."  The  reverse  drum  of  the 
platform  controller  is  replaced  by  a  similar  drum,  ex- 
cept that  it  is  more  liberal  in  capacity,  built  in  a  sep- 


Figure  115— Unit  Switch. 


MULTIPLE-UNIT    CONTROL. 


123 


arate  case  and  moved  to  the  forward  or  reverse  posi- 
tion by  one  or  the  other  of  two  cylinders  having  a 
common  piston  rod.  This  device  is  called  a  "reverser" 
(Figure  117).  The  overhead  circuit-breaker  is  re- 
placed by  a  "line  switch,"  which  is  essentially  the 
same  as  one  of  the  switches  of  the  switch  group,  except 
that  it  is  placed  in  a  case  by  itself  and  is  provided 
with  an  automatic  trip,  which  causes  it  to  open  in  case 
of  an  overload  or  short-circuit.  These  three  pieces  of 


Figure  117 — Reverser. 

apparatus  effect  the  various  necessary  connections  be- 
tween motors,  resistance  and  trolley. 

Forming  an  essential  part  of  the  pneumatic  cylin- 
der for  operating  the  switch  group,  line  switch  and  re- 
verser  is  a  magnet  valve  which  governs  the  admission 
or  escape  of  air  to  or  from  that  cylinder.  These  mag- 
net valves  are  operated  by  means  of  a  small  storage 
battery,  and  their  opening  or  closing  is  regulated  by 
means  of  a  "master  controller"  to  which  their  circuits 
are  led.  The  switch  group,  reverser  and  line  switch 


124 


THE    MOTORMAN. 


MULTIPLE-UNIT    CONTROL.  125 

thus  may  be  located  in  any  convenient  position,  while 
nothing  but  the  master  controller  need  be  located  on 
the  platform,  and  only  the  small  low-voltage  battery 
circuits  be  carried  to  it. 

For  train  operation  the  circuits  from  the  battery 
and  magnets  are  carried  to  "train  line  receptacles"  at 
each  end  of  the  car,  as  well  as  to  the  master  controllers, 
and  when  two  cars  are  coupled  together  the  corre- 
sponding receptacles  on  each  car  are  then  connected  by 
a  multipoint  "jumper,"  so  that  the  circuits  are  con- 
tinued from  car  to  car.  When  several  cars  are  con- 
nected in  this  way  the  movement  of  a  single  master 
controller  closes  simultaneously  the  corresponding 
magnet  circuits  on  all  of  the  cars  and  thus  operates 
also  the  corresponding  main  circuit  switches. 

Connected  to  the  piston  rods  which  move  the  va- 
rious switches  are  a  number  of  small  contact  switches 
which  open  or  close  auxiliary  circuits  between  station- 
ary fingers  arranged  to  press  on  them.  The^e  auxiliary 
contacts  are  called  "interlocks,"  and  the  circuits  which 
operate  the  magnet  valves  of  each  of  the  various 
switches  are  carried  through  the  interlocks  of  other 
switches  in  such  a  way  that  the  switches  cannot  be 
closed  except  in  the  proper  order. 

The  unit-switch  control  system  (Figure  118),  how- 
over,  does  not  consist  merely  in  replacing  the  ordinary 
controller  with  a  set  of  pneumatic  switches,  which  may 
be  closed  properly  or  improperly  entirely  at  the  discre- 
tion of  the  motorman,  but  the  action  of  the  switches 
is  regulated  by  means  of  a  "limit  switch,"  so  as  to 
give  a  uniform  current  through  the  motors  while  oper- 
ating on  the  resistance  steps;  thus  securing  a  smooth 
and  even  acceleration  of  the  car  and  protecting  the 
equipment  from  overload.  This  limit  switch  consists 


126  THE    MOTORMAN. 

of  a  coil,  placed  in  series  with  the  motor  circuits, 
which  lifts  an  armature  whenever  the  current  exceeds 
a  predetermined  amount. 

The  circuits  for  closing  the  various,  switches  of  the 
switch  group  are  so  arranged  that  it  is  not  necessary 
to  move  the  master  controller  step  by  step  to  cause  the 
closing  of  the  different  switches,  but,  by  placing  the 
master  controller  in  a  single  definite  position  and  hold- 
ing it  there,  the  circuits  to  the  first  switches  are  closed. 
The  closing  of  these  switches  then  automatically  closes 
the  next  ones,  etc.,  by  means  of  the  interlocks.  The 
circuit  from  the  battery  which  supplies  power  for  this 
automatic  operation  is  led  through  the  secondary  con- 
tacts of  the  limit  switch,  so  that  as  long  as  the  current 
through  the  motors  does  not  exceed  the  desired  value, 
the  different  switches  will  close  one  after  the  other 
almost  instantaneously.  Should  the  current  through 
the  motors  at  any  time  exceed  the  desired  amount,  how- 
ever, the  armature  of  the  limit  switch  will  instantly 
rise  and  thus  prevent  the  closing  of  any  more  switches 
until  the  current  has  fallen  to  the  desired  value. 

The  regulation  of  the  current  during  starting  is 
thus  taken  entirely  out  of  the  hands  of  the  motorman, 
who  simply  advances  the  handle  of  the  master  con- 
troller to  the  last  notch  and  holds  it  there ;  the  closing 
of  the  switches  is  then  governed  automatically  by  the 
limit  switch.  In  order  to  provide  for  the  handling  of 
the  car  under  special  conditions,  the  apparatus  is  so 
arranged  that  the  motorman  may  readily  notch  up 
more  slowly  than  would  be  done  by  the  limit  switch, 
or  may  stop  at  any  notch ;  also,  by  going  to  some  extra 
trouble  he  can  short-circuit  the  limit  switch  and  notch 
up  entirely  independent  of  the  current. 

As  ordinarily  built,  the  master  controller  (Figure 


MULTIPLE-UNIT    CONTROL. 


127 


119)  for  use  with  the  unit-switch  control  system  con- 
tains three  notches  for  forward  running  and  three  for 
reverse.  If  the  handle  is  moved  to  the  first  notch  a 
slow-speed  resistance  point  is  obtained  which  is  used 
principally  in  shifting  cars.  This  first  notch  hence  is 
called  the  "switching"  position.  If  the  handle  is 
moved  to  the  second  notch,  either  with  or  without  paus- 
ing on  the  first  one,  the  switches  close  one  after  the 
other  until  the  motors  are  con- 

; — ^-? n        nected  in  series.    The  second  notch 

m  is   therefore   called   the   "series" 

position,  and  is,  of  course,  a  run- 

^diC±SBBfe          '  ning  point.  If  the  handle  is  moved 

lr.  .,'V:^  to  the  third  notch,  either  at  once 

,          H,/|'  or  after  pausing  on  one  or  both  of 

^J^j  the  first  two  notches,   additional 

M  ;  ••I          switches    will    then    close    in    se- 

£'  ""'  quence  until  the  motors  are  con- 

4  nected,  in  full  multiple.    The  third 

notch  is  called  the  "parallel"  po- 

|j :  sition. 


Figure  119 
Master  Controller. 


An  interesting  detail  to  learn 
in  connection  with  this  system  of 
control  is  the  method  of  charging 

the  small  storage  batteries  used  for  operating  the  mag- 
net valves.  Two  batteries  are  carried  on  a  car,  and  these 
are  connected  to  the  air-pump  motor  circuit,  as  shown 
in  Figure  118.  The  two  double-throw  switches  are 
always  thrown  either  both  up  or  both  down,  so  that 
one  battery  is  connected  to  the  control  circuit  while  the 
other  is  being  charged.  Whenever  the  pump  is  run- 
ning the  battery  which  is  being  charged  is  connected 
by  the  "battery-charging  relay"  to  the  circuit  of  the 
pump  motor.  The  resistance  in  series  with  the  pump 


128  THE    MOTORMAN. 

motor  is  so  adjusted,  in  connection  with  the  relative 
amount  of  time  that  the  pump  is  running  and  the 
control  circuits  are  closed,  that  the  battery  will  re- 
ceive on  the  one  hand  sufficient  current  to  charge  it 
properly,  without,  on  the  other  hand,  receiving  enough 
current  to  make  it  boil  or  gas.  When  this  adjustment 
once  has  been  made,  the  batteries  will  require  little  at- 
tention other  than  the  reversal  of  the  two  switches  once 
each  day. 

Another  detail  of  the  equipment  is  the  air-storage 
system.  A  separate  c; control  reservoir"  is  piped  to  the 
air-brake  system,  as  shown  in  Figure  118,  in  connection 
With  a  "governor"  or  check  valve  and  a  three-way 
valve.  Ordinarily  the  three-way  valve  is  turned  so  that 
the  air  is  drawn  directly  from  the  brake  system,  but  in 
case  of  accident  to  the  compressor  or  main  reservoir 
the  three-way  valve  may  be  turned  through  a  right 
angle  and  the  reserve  supply  of  air  in  the  control  reser- 
.voir  thus  be  made  available  to  return  the  car  to  the 
car  house. 

In  providing  for  the  control  of  the  different  sizes 
of  motors  most  commonly  used,  two  sizes  of  switch 
groups  are  employed.  This  method  of  control,  Avith 
slight  modification,  is  adaptable  to  either  direct  or  al- 
ternating current,  or  both,  as  shown  in  Figure  120 
at  end  of  book. 


CHAPTER  IX. 


OPERATION    OF    CONTROLLERS. 

The  value  of  an  employe  depends  upon  the  econ- 
omy with  which  he  can  operate  his  car — economy  in  the 
way  of  preventing  costly  accidents,  economy  in  power 
and  economy  in  wear  and  tear  of  the  cars,  trucks  and 
motors  he  runs.  What  has  been  said  before  has  been 
intended  to  prepare  the  reader  for  this  chapter,  which 
deals  directly  with  an  employe's  actual  duties.  It 
does  not  require  any  special  knowledge  to  be  able  to 
get  a  car  over  the  road.  To  operate  it  in  the  best  possi- 
ble manner  is  quite  another  matter.  It  is  the  main 
object  of  this  book  to  tell  electric  railway  employes 
how  to  make  themselves  valuable  men ;  how  to  operate 
a  car  with  greatest  economy. 

Let  the  operation  of  controllers  first  be  considered, 
beginning  with  the  series-parallel  controllers  which 
are  in  common  use  today.  The  operation  of  all  the  con- 
trollers is  very  simple.  They  all  have  reverse  levers  at 
the  right  of  the  stand  or  on  the  top,  and  the  controlling 
handle  on  nearly  all  is  moved  around  in  the  direc- 
tion of  the  hands  of  a  watch  to  turn  on  the  current,  and 
in  the  opposite  direction  to  turn  off  the  current.  Be- 
fore trying  to  start  a  car,  first  be  sure  that  the  brakes 
are  off,  that  the  controller  handle  at  the  other  end  of 


130  THE    MOTORMAN. 

the  car  is  on  the  "off"  position  and  the  canopy  switches 
are  closed.  Then  move  the  controller  handle  to  the 
first  notch.  The  car  will  start  if  all  is  right.  After  the 
car  is  well  under. way  on  the  first  notch,  move  to  the 
second,  and  so  on  to  the  last.  In  moving  from  one  notch 
to  another  do  not  stop  the  handle  between  notches,  but 
give  it  a  push  strong  enough  so  that  it  will  go  to  the 
next  notch.  A  timid  or  inexperienced  motorman  is  apt 
to  turn  the  handle  slowly,  but  this  is  bad  practice. 

Always  wait  long  enough  on  each  notch  for  the  car 
to  gain  speed  before  passing  to  the  next  notch.  If  this 
is  not  done,  much  more  current  than  necessary  may  be 
used  to  move  the  car.  The  wheels  may  slip,  the  motors 
will  be  strained  and  overheated,  and  there  will  be  a 
great  drain  on  the  power  station  generators,  and  wear 
on  machinery.  When  the  notch  is  reached  where  the 
motors  are  in  series  and  there  is  no  rheostat  resistance 
in  the  circuit,  special  care  should  be  taken  to  let  them 
gain  speed  and  run  up  to  nearly  the  maximum  speed 
they  can  attain  in  this  position  before  passing  to  the 
higher  notches  where  the  motors  are  in  parallel.  When 
the  motors  are  thrown  in  parallel  too  soon  in  starting, 
a  waste  of  power  takes  place.  This  notch  on  which  the 
motors  are  in  series  with  no  rheostat  resistance  in  the 
circuit  is  indicated  by  a  long  mark  on  the  top  of  the 
controller.  It  is  on  this  series  point  that  the  motors 
exert  the  greatest  pull  with  the  least  current,  and  it 
should  preferably  be  used  when  there  is  heavy  pulling 
to  be  done  or  steep  grades  to  be  climbed. 

On  looking  at  the  points  marked  on  the  controller 
tops  it  will  be  seen  that  some  of  them  are  marked  with 
longer  or  heavier  marks  than  the  others.  Those  points 
with  long  marks  are  called  "running"  points,  because 
on  them  the  motors  may  be  operated  for  any  length 


OPERATION    OF    CONTROLLERS.  131 

of  time  without  overheating  or  wasting  current  in  the 
rheostats.  Among  these  running  points  there  are 
some  to  be  preferred  because  on  them  the  whole  energy 
taken  into  the  motors  is  used  to  propel  the  car.  These 
preferred  points  are  those  positions  on  which  no  rheo- 
stat resistance  or  diverter  is  left  in  circuit  with  the 
motors. 

On  the  K-10  controller  the  preferred  running  point 
is  the  fifth,  at  which  the  motors  are  in  series  and  resist- 
ance all  cut  out.  This  should  be  used  for  slow  running. 
It  gives  half  full  speed.  The  ninth  point  is  the  high- 
speed point,  and  is  for  use  only  on  a  level.  Use  of  the 
fifth  or  ninth  points  on  grades  is  very  wasteful  of  cur- 
rent and  hard  on  the  motors,  and  little  is  gained  by  it 
in  the  way  of  speed. 

In  shutting  off  current  the  controller  handle  should 
be  brought  rapidly  to  the  off  position  from  whatever 
point  it  may  happen  to  be  on,  without  stopping  at  any 
point.  To  run  the  car  backward  when  it  is  standing, 
pull  the  reverse  lever  back  and  turn  on  the  current  as 
when  running  forward.  Sometimes  it  is  necessary  to  re- 
verse when  the  car  is  running  ahead,  in  order  to  avoid 
running  into  something.  To  do  this,  throw  the  con- 
troller handle  to  "off"  and  pull  back  the  reverse  han- 
dle. Then  move  the  controller  to  the  first  notch.  The 
car  will  stop  with  a  jerk  and  begin  to  go  backward. 
This  way  should  be  resorted  to  only  when  there  is  dan- 
ger, and  even  then  the  car  speed  should  be  slow,  be- 
cause it  is  not  a  sure  remedy.  The  fuse  may  blow  and 
thereby  suddenly  shut  off  the  power  on  account  of  the 
abnormally  heavy  current  flowing.  There  is  also  a 
possibility  that  one  or  the  other  motor  may  be  per- 
manently disabled. 

There  is  one  way,  however,  in  which  a  violent  stop 


132  THE    MOTORMAN. 

can  be  made  with  a  series-parallel  controller,  even 
when  the  power  is  cut  off  and  the  brakes  fail.  It  is 
done  by  reversing  if  the  car  is  moving  ahead,  or  throw- 
ing the  reverse  level  "ahead"  if  the  car  is  backing,  and 
putting  the  controller  handle  on  the  highest  point  of  the 
controller.  In  this  case  the  motors  act  as  dynamos,  gen- 
erating current.  This  method  may  be  used  in  emergen- 
cies when  the  brakes  are  not  sufficient  and  the  trolley 
has  come  off  or  the  fuse  has  blown  and  the  car  is  go- 
ing down  an  incline. 

It  may  never  have  to  be  used,  and  it  is  not  cred- 
itable to  have  to  use  it  by  letting  a  car  get  beyond  con- 
trol ;  but  the  brake  may  give  out  or  something  else 
happen  beyond  the  control  of  the  motorman,  so  it 
should  always  be  remembered,  as  it  may  save  a  sad  acci- 
dent some  day.  In  case  you  have  reversed  and  the  fuse 
blows,  the  instant  it  is  felt  that  the  power  has  been  shut 
off  by  the  blowing  of  the  fus£,  put  the  controller  around 
on  one  of  the  higher  points  named.  This  plan  may  also 
be  used  in  case  the  brakes  fail  and  the  trolley  comes 
off  going  down  hill.  It  is  a  very  violent  way  of  stop- 
ping, and  injurious  to  the  equipment. 

Hints  on  Saving  Power.— It  is  not  necessary  that  a 
man  be  powerful  to  control  an  electric  car.  At  first  he 
is  apt  to  spend  a.n  unnecessary  amount  of  energy  at 
the  brake.  Power  may  be  saved  and  the  car  would  be 
subject  to  less  wear  and  tear  if  handled  not  by  pure 
strength,  but  by  proper  judgment  of  time  and  distance. 
It  should  be  considered  that  as  long  as  the  controller 
is  not  on  the  "off"  .position  power  is  tal«;en  into  the 
motors  and  consumed.  If  a  car  is  to  be  stopped,  turn 
off  the  power  some  time  ahead,  because  the  energy 
taken  into  the  motor  does  not  disappear  the  moment 
the  current  is  shut  off.  The  motors  and  the  car  have 


OPERATION    OF    CONTROLLERS. 


133 


weight,  and  energy  is  stored  in  this  moving  body  and 
this  energy  must  be  spent  before  the  car  can  come  to 
rest.  Some  men,  because  they  have  not  the  right  judg- 
ment, set  the  brake  the  moment  the  controller  is  placed 
at  the  "off"  position,  and  they  must  then  work  hard  at 
the  brake  and  consume  the  energy  still  stored  in  the 
moving  car,  by  spending  it  partly  in  wear  on  them- 


Figure  121 — Curves  Showing  Power  Required  for  Correct  and   Incor- 
rect Handling  of  Controller. 

selves,  brakeshoes,  car  wheels,  motors  and  gears.     It 
means  wear  all  around,  without  benefit  to  anyone. 

A  test  (Figure  121)  made  by  the  author  between 
a  good  and  a  poor  motorman  with  the  same  motor  car 
and  same  load,  on  the  same  dry  summer  day,  showed 
that  the  better  man  used  but  one-half  as  much  power 
as  the  other.  What  became  of  the  extra  energy  used 
by  the  other  man  ?  The  answer  is  found  in  the  barn  at 


134  THE    MOTORMAN. 

the  end  of  the  day.  The  man  who  uses  the  most  power 
seems  tired  when  he  goes  home  in  the  evening,  from  the 
hard  work  he  had  at  the  brake;  and  an  examination  of 
the  equipment  will  show  the  greater  wear  on  brake- 
shoes,  constant  trouble  with  brakes,  softer  car  wheels, 
which  soon  wear  flat  in  spots,  and  frequent  loose  bolts, 
all  caused  by  this  extra  expenditure  of  energy  by  the 
man  of  no  experience  or  poor  judgment.  The  simplest 
thing  in  the  world  is  to  cut  off  the  power  ahead  of  time 
and  let  the  energy  stored  in  the  car  spend  itself  by  al- 
lowing it  to  propel  the  car  by  its  momentum  for  half  a 
block  or  so,  when  it  easily  can  be  stopped  by  setting  the 
brake.  What  has  been  said  here,  however,  is  not  always 
possible  to  do,  and  a  motorman  must  use  his  judgment. 
For  instance,  if  the  pressure  (voltage)  is  low,  or  many 
stops  have  to  be  made,  or  the  motors  have  not  speed 
enough  for  the  schedule  time  set  by  the  company,  a 
motorman  cannot  act  exactly  as  he  would  wish.  But  in 
these  cases  the  conditions  are  not  normal.  Such  rules 
can  be  used  as  a  guide  when  a  road  is  properly 
equipped  and  the  schedule  time  for  a  round  trip  is  so 
chosen,  compared  with  the  distance  to  be  covered  and 
speed  of  the  motors,  that  the  motors  can  accomplish 
their  work  easily. 

When  running  up  behind  a  team  on  the  track  and 
it  is  seen  that  the  car  will  overtake  it  before  it  gets 
out  of  the  way,  do  not  crowd  on  speed  and  rush  up 
behind  it,  as  is  often  done,  only  to  be  obliged  to  put 
the  brakes  on  hard  to  avoid  a  collision.  Just  as  good 
time  will  be  made  and  much  muscle  and  power  be  saved 
by  letting  the  car  run  along  slowly  enough  to  get  the 
team  out  of  the  way  before  reaching  it  instead  of  bring- 
ing the  car  almost  to  a  stop  after  having  run  up  to  it 
at  full  speed. 


OPERATION    OF    CONTROLLERS.  135 

Should  the  wheels  slip  or  skid  on  going  up  grade, 
bring  the  sand  box  into  action,  and  if  the  car  wheels 
continue  to  slip  then  throw  the  controller  handle  to  the 
"off"  position  and  turn  it  on  again  step  by  step.  When 
the  rail  is  greasy  or  covered  with  snow  so  that  the 
wheels  do  not  take  hold  of  the  rail,  apply  a  little 
sand  before  starting  the  car.  Use  the  sand  sparingly 
and  be  sure  that  there  is  some  left  for  future  use. 

Some  Precautions  Against  Accidents.— When  ap- 
proaching curves,  switches,  turnouts  or  railroad  cross- 
ings slow  down  the  car  so  as  to  have  it  under  control. 
It  is  best  to  have  the  controller  at  the  "off"  position 
and  the  right  hand  on  the  brake.  The  moment  the 
wheels  reach  the  curve,  switch  or  crossing  put  on  the 
power  gradually,  to  carry  the  car  over  the  curve  or 
crossing.  Never  let  the  ear  stop  on  short  curves  such 
as  are  frequently  found  on  city  lines,  unless  special  in- 
structions from  the  company  have  been  issued  on  this 
point.  When  taking  curves  or  turnouts  the  conductor 
should  be  on  the  rear  platform  ready  to  replace  the 
trolley  should  it  jump  the  wire.  If  the  trolley  passes 
the  curve  or  switch  properly,  the  conductor  should 
ring  "go  ahead";  if  the  trolley  jumps  he  should  ring 
"stop."  If  the  conductor  has  given  his  signal  that 
the  trolley  has  jumped  off  the  wire,  the  motorman 
should  keep  his  controller  handle  at  the  "off"  position 
until  the  conductor  rings  "go  ahead." 

When  going  around  curves,  crossings  or  other 
places  where  the  car  may  jump  the  track  owing  to 
roughness  of  the  roadbed,  or  where  rails  are  laid  very 
low  in  a  gravel  road,  and  stones  may  wedge  in  the  rails, 
or  when  passing  through  flooded  places  or  low  places 
where  the  rails  are  covered  with  water,  slow  speed 
should  be  used.  When  going  up  grades,  it  is  best  to 


136  THE    MOTORMAN. 

put  the  controller  on  points  where  the  resistance  is  cut 
out,  and,  further,  the  car  should  not  be  stopped  or 
started  on  a  heavy  grade  if  it  can  be  avoided. 

When  passing  an  overhead  insulated  switch  or  sec- 
tion insulator,  place  the  controller  always  at  the  "off" 
position,  unless  on  a  grade  or  there  are  other  instruc- 
tions from  the  superintendent. 

Going  down  grade  have  the  controller  handle  at 
the  "off"  position,  the  trolley  on  the  trolley  wire  and 
the  brake  set  to  such  an  extent  that  the  wheels  turn 
slowly  (not  slide)  so  that  the  car  remains  under  con- 
trol, slackening  the  hold  on  the  wheels  when  the  grade 
becomes  less  steep  or  tightening  the  grip  of  the  brake- 
shoes  should  the  grade  become  steeper.  Should  the  car 
get  beyond  control  or  the  brake  suddenly  give  out,  it 
may  be  necessary  to  resort  to  reversing  the  controller, 
as  previously  explained.  It  is  a  severe  strain  on  the 
motors,  but  may  have  to  be  resorted  to,  to  prevent  an 
accident  or  to  save  lives.  When  so  reversing  keep  the 
controller  in  the  first  notch  should  it  be  effective;  if 
not,  turn  the  handle  very  slowly  to  the  higher  notches, 
as  the  fuse  is  liable  to  give  out  and  the  control  by 
means  of  current  from  the  power  station  is  gone.  Should 
the  fuse  blow  there  is  then,  as  before  mentioned,  only 
one  more  way  to  get  the  car  under  control,  and  that  is 
to  throw  the  controller  to  the  last  notch,  which  causes 
the  motors  to  act  as  dynamos.  This  plan  is  available 
only  when  there  are  two  o*  more  motors  on  a  car.  The 
current  is  generated  by  the  rotation  of  the  armature  in 
the  field.  The  energy  furnished  is  the  momentum  of 
the  descending  car,  which  is  out  of  your  control  and 
disconnected  from  the  power  station.  The  current  so 
generated  acts  by  means  of  the  armatures  as  a  brake, 
and  the  car  will  slow  up  in  the  same  measure  as  the 


OPERATION    OF    CONTROLLERS.  137 

motors  generate  current.  The  means  just  described  are 
important  to  know,  but  should  never  be  resorted  to  ex- 
cept  in  extreme  cases. 

When  stopping  a  car  in  the  barn  pull  down  the 
trolley  one  foot  or  a  foot  and  a  half  and  tie  it;  also 
see  that  both  controllers  are  on  the  "off"  position  and 
open  the  overhead  or  canopy  switch.  If  for  any  reason 
the  trolley  should  be  left  on  the  wire  in  the  barn  some 
of  the  car  lamps  might  be  turned  on,  which  will  be  a 
warning  to  the  repair  men. 

Before  starting  see  that  the  controllers  on  both 
platforms  are  on  the  "off"  position.  Never  place  tools, 
rubber  boots  or  other  wearing  apparel,  cotton  waste  or 
the  like  on  the  side  below  the  seat  where  the  motor  cut- 
out or  wire  cable  connecting  controllers  and  motors  are 
located.  Keep  this  place  clean  and  free  from  dirt  and 
moisture. 

When  examining  motors  open  the  main  or  over- 
head switch  and  take  care  not  to  let  water  drop  into 
the  motor  from  wet  clothing.  When  examining  car 
motors,  fuse,  etc.,  always  open  the  overhead  switch  to 
avoid  shocks.  When  operating  a  car,  any  unusual  noise 
heard  should  be  located.  Loose  bolts  should  be  re- 
ported and  attended  to,  because  by  the  fixing  in  proper 
time  of  these  small  irregularities,  which  are  caused  by 
jarring  and  constant  operation  of  the  car,  grave  trouble 
can  be  prevented,  and  a  car  will  remain  much  longer 
in  good  repair  if  kept  so  and  watched. 

It  is  true  that  a  "stitch  in  time  saves  nine."  The 
writer  has  seen  plants  where  cars  were  neglected,  bolts 
could  be  picked  up  along  the  road,  and  on  one  occasion 
a  car  was  stalled  because  the  lower  half  of  a  field  mag- 
net had  dropped  down  and  was  wedged  against  the 
stone  pavement.  Should  a  motorman  notice  irregu- 


138  THE    MOTORMAN. 

larities  or  defects  on  the  overhead  line  or  on  the  track, 
the  matter  should  be  reported. 

When  operating  on  a  road  with  steep  grades  be 
sure  that  you  are  prepared  in  damp  or  slippery  weather 
to  be  able  to  get  sand  from  the  boxes.  It  is  not  suffi- 
cient that  there  is  sand  in  them ;  it  should  be  seen  that 
it  is  dry  sand  and  that  the  valve  is  in  such  condition 
as  to  allow  the  sand  to  pass  through. 

Never  shift  the  reversing  handle  unless  the  con- 
troller handle  is  on  the  "off"  position,  nor  reverse 
when  the  car  is  in  motion  except  to  prevent  an  accident. 

When  leaving  the  platform  be  sure  that  the  con- 
troller is  turned  off  and  remove  the  controller  handle. 
When  on  the  road  they  should  be  kept  in  the  hand,  and 
in  the  barn  they  should  be  left  according  to  the  rules 
given  by  the  company.  The  reason  the  motorman 
should  not  leave  the  controller  handle  on  the  controller 
is  that  accidents  are  encouraged.  The  author  has  fre- 
quently seen  that  at  country  fairs,  where  people  crowd 
into  the  cars  at  both  ends,  people  are  apt  to  strike  the 
handle  with  baskets  or  coats  held  over  the  arm,  and 
can  in  this  way  start  the  car  unexpectedly.  Keeping 
the  handle  in  one's  hand  on  such  occasions  leaves  the 
motorman  in  full  control  of  his  car  and  up  to  the  re- 
quirements of  his  duty  and  responsibility. 

Young  people  do  not  realize  the  responsibility  of 
the  position  of  a  motorman;  they  may  think  it  fun  to 
hide  the  handle  when  he  has  left  the  car  for  a  moment. 
Persons  acquainted  with  the  motorman  have  taken 
such  liberties  when  a  car,  for  instance,  was  at  the 
end  of  a  track  and  had  to  wait  for  five  or  ten  minutes. 
As  the  motorman  is  held  responsible  for  his  car  he 
should  always  have  it  under  full  control,  and  leave  it 
so  no  one  can  accidentally  start  it. 


OPERATION    OF    CONTROLLERS.  139 

If  at  any  time  the  power  gives  out  in  the  power 
station,  for  instance,  by  the  operating  of  a  circuit- 
breaker,  then  bring  the  controller  handle  to  the  "off" 
position,  close  the  lamp  circuit  and  wait  until  the  lamps 
light. 

Before  starting  the  car  for  a  run,  see  that  the 
brushes  and  brush  springs  are  in  position  (unless  there 
is  someone  else  whose  duty  it  is  to  keep  the  cars  in 
readiness  for  the  motorman).  Before  placing  the  trol- 
ley on  the  wire,  look  at  both  controllers  and  be  sure 
that  they  are  both  at  the  "off"  position.  Do  not  run 
the  car  with  the  trolley  pole  in  the  wrong  direction,  be- 
cause in  this  position  it  has  no  yielding  properties  when 
it  strikes  a  hanger  or  suspension  wire.  If  it  jumps  the 
wire  it  would  bend  the  pole  or  cause  trouble  to  the 
overhead  wire. 

The  operation  of  the  brakes  is  one  of  the  most 
important  duties  of  a  motorman  and  one  of  the  most 
difficult.  Accordingly,  it  is  treated  in  a  chapter  by 
itself. 


CHAPTER  X. 


BRAKES    AND    THEIR    OPERATION. 


The  brake  is  a  most  important  device  for  the 
motorman,  because  its  purpose  is  to  control  the  car 
when  the  power  is  cut  off  and  force  it  to  slow  up  or 
stop  at  any  desired  place.  The  brake,  when  applied, 
consumes  the  energy  stored  in  the  car  by  the  motors. 
This  energy  is  overcome 
by  the  friction  of  the 
brakeshoes  (Figure  122) 
on  the  car  wheels.  The 
better  a  motorman  can 
estimate  the  distance 
and  the  less  he  has  to 
use  the  stored  energy 
by  applying  the  brake, 
the  more  efficient  is  his 

Service,    and    the    leSS    is          Figure  122—  Brakeshoe  and  Head. 

the  power  wasted.     To 

apply  the  powrer  up  to  the  last  moment  and  immedi- 
ately afterward  use  the  brake  is  a  wasteful  perform- 
ance, although  when  stopping  on  a  grade  or  when  a 
motorman  has  to  make  many  stops  and  his  time  for  a 
round  trip  is  measured  closely  with  respect  to  the  speed 
of  the  motor  in  use,  such  action  cannot  be  avoided. 


BRAKES    AND    THEIR    OPERATION.  141 

There  are  at  present  in  use  five  kinds  of  brakes. 

1.  Hand  brakes  in  which  the  power  which  draws 
the  brakeshoes  against  the  wheels  is  supplied  by  the 
strength  of  the  motorman,  either  by  the  winding  of  a 
chain  on  a  staff  or,  as  on  a  few  roads,  by  a  long  lever. 

2.  Momentum  or  friction  disc  brakes  in  which  the 
momentum  of  the  car  furnishes  power  to  draw  up  the 
brakeshoes  through  the  medium-  of  a  friction  disc  or 
clutch  placed  on  one  axle. 

3.  Air  brakes,  in  which  the  power  drawing  up  the 
brakeshoes  is  compressed  air  acting  against  a  piston. 

4.  Electric  brakes,  in  which  the  retarding  force 
is  the  electricity  generated  in  the  motors  which  are 
connected  to  act  as  dynamos,  the  motors  in  this  case 
being  used  to  stop  the  car  as  well  as  to  start  it  and 
run  it. 

5.  Track  brakes,  in  which  shoes  carried  at  the 
sides  of  the  truck  are  pressed  against  the  top  of  the 
track  rails  with  sufficient  force  so  that  the  friction  be- 
tween the  shoes  and  rail  stops  the  car. 

Hand  Brakes. — While  hand  brakes  are  used  on  all 
electric  cars,  all  but  the  smallest  and  lightest  cars  are 
now  generally  equipped  with  some  kind  of  power 
brakes.  Every  truck  has  a  brake  mechanism  consisting 
of  various  arrangements  of  rods,  beams  and  levers 
by  means  of  which  the  force  applied  to  the  brake 
handle  or  the  brake  levers  is  transmitted  to  the  brake- 
shoes  so  that  they  may  be  pressed  hard  against  the 
wheels.  Different  makes  of  trucks  have  their  own 
styles  of  brake  rigging.  The  number  of  different 
makes,  however,  is  too  great  to  permit  a  detailed  de- 
scription of  them  all,  and  as  the  general  arrangement 
of  all  of  them  is  more  or  less  similar,  a  description  of 
two  or  three  different  styles  of  brakes  will  suffice. 


142 


THE    MOTORMAN. 


Figure  124. 


BRAKES    AND    THEIR    OPERATION.  143 

Figures  123,  124  and  125  show  three  views  of  the 
truck  equipped  with  hand  brakes.  Figure  123  is  a 
top  view,  Figure  124  a  front  elevation  and  Figure  125 
a  side  elevation.  The  brakeshoes,  5,  are  located  close 
behind  the  car  wheels  1,  2,  3  and  4,  the  normal  distance 
between  the  brakeshoes  and  wheels  being  about  one- 
eighth  of  an  inch.  The  shoes  are  supported  by  brake- 
beams,  6,  to  which  are  fastened  the  brake  rods,  7.  The 
other  ends  of  the  brake  rods  are  securely  fastened  to 
the  cross  beams,  8,  which  in  turn  engage  at  9  with  the 
equalizer  bar.  At  the  ends  of  the  equalizer  bar  are 
secured  the  hook  rods,  11,  into  which  the  brake  chain 
is  hooked.  The  chain,  brake  staff  and  handle  are  not 
shown  in  these  drawings.  A  heavy  spring,  12,  is  used 
to  remove  the  brakeshoe  from  the  car  wheels  when  the 
brake  is  released.  The  action  that  takes  place  in  brak- 
ing the  car  is  as  follows: 

When  the  motorman  turns  the  brake  handle  around 
one  or  more  turns  he  winds  up  the  brake  chain  and 
pulls  forward  the  hook  rod,  11,  thereby  moving  the 
equalizer  bar,  10,  which  in  turn  moves  the  cross  beams, 
8,  8.  These  cross  beams  in  moving  toward  each  other 
move  rods  7,  and  these  in  turn  bring  the  brakebeams, 
6,  and  shoes,  5,  toward  each  other  until  the  shoes  rest 
firmly  against  the  car  wheels.  When  the  brake  handle 
is  released,  all  the  parts  return  to  their  former  position. 
The  spring,  12,  assists  in  this  latter  work  and  helps  to 
hold  the  brakeshoe  away  from  the  wheel. 

It  will  be  seen  from  this  that  all  four  brakeshoes 
act  at  the  same  time.  It  is  necessary  to  provide  an 
adjustment  in  every  brake,  because  the  brakeshoes 
wear  and  the  slack  caused  by  this  wear  must  be  taken 
up.  In  the  truck  just  described  this  adjustment  is  made 
where  the  rods,  7,  connect  to  the  brakebeam  at  points 


144  THE    MOTORMAN. 

14,  near  the  shoes.  These  rods  have  threaded  ends 
that  screw  into  sleeve  nuts,  15,  which  are  held  in  pock- 
ets provided  for  them  in  the  brakebeam.  A  self-lock- 
ing device  prevents  these  ends  from  turning  loose  by 
the  jolting  of  the  car.  The  adjustment  is  made  by 
turning  the  head  of  the  nut  with  a  wrench.  The  head 
is  at  the  outer  enclosed  side  of  the  nut,  and  turning  it 
to  the  right,  or  clockwise,  shortens  the  rod  and  brings 
the  shoe  nearer  the  wheel.  The  locking  device  does  not 
interfere  with  turning  the  nut  with  a  wrench,  but  it 
prevents  the  nut  from  turning  due  to  the  jolting  of 
the  car.  These  adjustments  are  placed  near  the  brake- 
shoes,  because  this  location  enables  the  adjustment  of 
each  shoe  separately,  and  consequently  all  the  shoes 
may  be  regulated  for  an  equal  pressure  on  their  wheels. 
On  double-truck  cars,  arrangements  are  made  to 
apply  the  brakes  on  both  trucks,  so  that  each  will  be 
operated  by  one  motion  of  one  brake  handle  or  one  air 
brake  cylinder.  This  is  accomplished  in  various  ways, 
generally  by  having  either  a  fixed  or  floating  lever  in 
the  center  of  the  car  between  the  trucks,  to  which  the 
brake  rods  from  each  truck  are  connected.  The  cen- 
tral lever  is  then  connected  to  the  brake  staff  by  means 
of  a  brake  chain  and  rod,  and  by  moving  this  rod  and 
the  central  lever  to  which  it  is  attached,  the  brakes 
on  both  trucks  are  operated  simultaneously.  Such  an 
arrangement  of  the  levers  for  double-truck  cars  is 
shown  in  Figure  126,  and  the  following  dimensions 
show  the  proportion  of  the  different  levers.  The  length 
of  the  floating  lever,  1,  is  48  inches,  and  the  distance,  d, 
between  the  pins  for  the  arch  bar  rods  is  9  inches.  The 
length,  b,  of  the  truck  lever  is  13  inches.  With  these 
dimensions  of  levers  a  pull  of  65  pounds  at  the  brake 
handle,  which  is  15  inches  in  length,  gives  a  total  brak- 


BRAKES    AND    THEIR    OPERATION. 


145 


ing  pressure  of  29,000  pounds,  which  is  more  than  the 
weight  of  an  empty  car.  The  proportion  of  the  levers 
recommended  by  the  makers  of  these  brakes  is  such  as 
to  make  (1-r-d)  X  (b-r-c)  X  (hX85)  equal  to  the  total 
weight  of  the  unloaded  car.  The  chain  is  not  coiled 
around  the  brake  staff  on  these  brakes.  Instead  there 
are  two  chains  running  in  a  double  sprocket  wheel, 
which  makes  the  operation  of  the  brake  very  smooth 


•  •  I'l  '•  "•  '.'  V™p 

I 


Figure  126 — Brake  Levers  on  One  Truck. 

and  permits  the  motorman  to  feel  even  a  slight  touch 
of  the  brakeshoe  against  the  wheel.  If  the  working 
chain  breaks,  the  safety  chain  comes  into  operation, 
thus  preventing  the  disability  of  the  brakes  from  this 
cause. 

The  object  of  these  brake  mechanisms  for  double 
trucks  is  to  provide  means  for  bringing  an  approxi- 
mately equal  pressure  on  all  of  the  car  wheels.  This 
is  necessary  in  order  to  secure  the  maximum  braking 
effect,  and  also  to  prevent  one  set  of  wheels  being 


146  THE    MOTORMAN 

locked  more  firmly  than  the  others,  which  would  cause 
them  to  slide  along  the  track  without  revolving  and 
produce  flat  spots  on  the  wheels. 

Electric  Brakes.— The  electric  brake  has  as  its 
fundamental  principle  the  utilizing  of  the  live  energy 
stored  in  the  moving  car  to  generate  an  electric  cur- 
rent in  the  motors  independently  of  the  power-station 
current,  and  the  use  of  this  current  to  bring  the  car  to  a 
standstill.  By  means  of  the  type  B  controllers,  as  de- 
scribed in  Chapter  VII,  the  motors  are  connected  to 
act  as  dynamos.  This  current  is  sent  through  resist- 
ance and  stops  the  car  partly  by  its  retarding  effect 
on  the  motors  themselves  and  partly  by  a  magnetic 
friction  disc  mounted  on  each  axle.  If  a  car  provided 
with  an  electric  brake  is  to  be  brought  to  a  stop,  the 
action  is  as  follows:  The  motorman  first  brings  his 
controller  to  the  "off"  position  and  thereby  disconnects 
the  car  from  the  line  and  power  station ;  then  by  mov- 
ing the  handle  around  to  the  left  of  the  "off"  position 
to  the  special  brake  notches,  the  armature  connections 
are  reversed  and  the  motors  are  connected  to  form  a 
closed  circuit  through  a  resistance  and  the  brake  disc 
magnets,  as  shown  in  Figure  127.  The  motors  running 
with  the  circuit  closed  in  this  way  act  as  dynamos  and 
generate  current.  This  current  tends  to  stop  the 
motors  and  also  to  cause  the  magnetic  clutch  on  the 
axle  to  act  and  aid  in  stopping  the  car. 

To  operate  an  electric  brake  requires  a  little  prac- 
tice on  the  part  of  the  motorman,  but  when  the  prin- 
ciple is  clear  it  is  an  easy  matter.  It  first  should  be 
understood  that  the  amount  of  current  generated  in 
the  motors,  and  consequently  the  braking  effect,  de- 
pend on  the  speed  at  which  the  motors  are  running. 
If  the  brakes  are  to  take  hold  evenly  from  the  begin- 


BRAKES  AND  THEIR  OPERATION. 


147 


ning  to  end  of  a  stop  the  resistance  which  is  in  the 
brake  circuit  must  be  cut  out  steadily.  For  example, 
when  it  is  desired  to  stop  a  car  that  is  running  at  full 
speed,  the  controller  handle  is  moved  to  the  first  brake 
point.  The  motors  start  generating  current  to  retard 
the  car,  but  as  the  car  slows  down  a  little  this  current 
begins  to  weaken,  and  the  handle  should  promptly  be 
moved  onto  the  next  point  to  cut  out  some  more  of  the 
resistance  from  the  brake  circuit  and  allow  more  cur- 


Figure  127 — Circuits  for  Magnetic  Brake. 

rent  to  flow,  and  so  on  until  the  car  is  stopped.  The 
motorman  should  promptly  advance  the  handle  from 
one  point  to  the  next  of  the  brake  controller  as  fast  as 
he  feels  the  current  failing  on  a  point.  The  quickness 
of  the  stop  will  depend  on  the  rapidity  with  which  the 
handle  is  moved  from  point  to  point,  and  in  emergencies 
it  may  be  found  necessary  to  move  two  or  more  points 
at  a  time.  There  never  is  need  to  reverse  on  a  car  hav- 
ing an  electric  brake,  because  the  brake  will  stop  the 
car  more  quickly  than  reversing  and  is  not  so  hard  on 


148 


THE    MOTORMAN. 


the  machinery.  On  grades  it  is  necessary  to  use  the 
hand  brake  to  hold  the  car  while  stopping,  because  the 
electric  brake  lets  go  as  soon  as  the  car  stops. 

Magnetic  Brakes.— The  Westinghouse  magnetic 
brake  consists  of  a  combination  of  a  track  brake  with 
the  ordinary  wheel  brake.  The  track  brakeshoe  is 
placed  between  the  wheels  on  a  truck  and  so  connected 
with  the  wheel  brakeshoes  that  when  the  current  in  the 
electro-magnet  of  the  track  brake  draws  the  shoe  down 


Figure  128 — Construction  of  Magnetic  Brake. 

on  the  rails  this  movement  forces  the  wheel  brakes 
against  the  wheel  treads.  This  not  only  adds  the 
track  brake  friction  to  the  wheel  friction  for  stopping 
the  car,  but  there  is  an  increase  in  the  wheel  pressure 
on  the  rails  due  to  magnetic  action.  The  construction 
of  this  brake  is  shown  in  Figure  128,  in  which  the  parts 
of  the  truck  are  in  dotted  lines  so  as  to  more  readily 
distinguish  the  brake  apparatus.  The  electro-magnet. 
a,  dividing  the  track  brakeshoe,  b,  into  two  parts,  is 
secured  by  pins  to  the  two  push  rods,  c,  and  suspended 
at  the  proper  distance  above  the  rails  by  the  adjustable 


BRAKES    AND    THEIR    OPERATION.  149 

springs,  h.  The  push  rods  are  secured  by  pins  to  the 
lower  ends  of  the  brake  levers,  d,  d.  These  brake  lev- 
ers are  connected  at  their  upper  ends  by  the  adjustable 
rod,  g,  and  at  an  intermediate  point  are  pivoted  to  the 
brakeshoe  holders  and  the  hanger  links,  f,  suspended 
from  the  truck  frame.  The  push  rods,  c,  are  telescopic, 
as  shown  in  the  sectional  view  of  the  one  at  the  left,  so 
that  a  movement  of  the  track  shoe  toward  the  right 
relative  to  the  truck  frame  causes  the  wheel  brake- 
shoe  at  the  right  to  be  applied  to  the  wheel  and  the 
connection,  g,  to  be  moved  to  the  left,  thereby  apply- 
ing the  wheel  brakeshoe  at  the  left.  The  stop,  i,  pre- 
vents the  lower  end  of  the  brake  lever  at  the  left  from 
following  the  track  brakeshoe.  A  relative  movement 
of  the  track  brakeshoe  to  the  left  is  obviously  accom- 
panied by  application  of  the  wheel  brakeshoes  through 
corresponding  movement  of  the  parts  in  the  reverse 
order. 

The  brake-controlling  device  may  be  incorporated 
in  the  running  controller  or  may  be  a  separate  device, 
placed  by  its  side  and  operatively  interlocked  with  it, 
so  that  neither  can,  through  carelessness,  be  caused 
to  interfere  with  the  operation  of  the  other.  These 
controllers,  type  B,  were  described  in  the  previous 
chapter.  In  the  operation  of  the  apparatus,  the  current 
is  supplied  by  the  motors,  running  in  multiple  as  gen- 
erators, and  is  divided  between  the  electro-magnets  and 
the  diverter,  in  such  ratio  as  to  cause  the  track  brake- 
shoes  to  be  drawn  upon  the  rails  with  a  force  pro- 
portionate to  the  braking  requirements.  The  frictional 
resistance  of  the  rails  to  the  motion  of  the  track  shoes 
causes  the  wheel  brakes  to  be  applied  with  correspond- 
ing force.  Thus,  to  the  ordinary  retardation  of  the 
wheel  brakes  is  added  that  of  the  track  brake.  The 


150  THE    MOTORMAX. 

force  of  application  depends  upon  the  current  and  upon 
the  electro-magnets  operating  the  brakeshoes.  The 
attractive  force  of  the  rails  upon  the  magnets  is  under 
the  control  of  the  motorman  up  to  a  limit  of  150  pounds 
per  square  inch  of  brakeshoe  surface  in  contact  with 
the  rails.  The  strength  of  the  magnet  is  limited  by 
the  sectional  area  of  the  rail,  acting  as  its  armature; 
and  where  the  weight  of  the  car  makes  desirable  a 
magnet  of  greater  strength,  the  track  shoe  is  divided 
into  three  parts,  instead  of  two,  and  wound  to  form 
a  three-pole  magnet,  or  two  electro-magnets  with  one 
common  pole.  With  this  brake  the  diverters  or  resist- 
ances are  arranged  in  two  sets,  one  inside  and  the  other 
outside  of  the  car.  Those  inside  are  used  to  heat  the 
car,  for  which  the  starting  current  and  braking  cur- 
rent are  ample.  The  two  sets  of  diverters  may  be  so 
combined  that  any  desired  portion  of  the  heat  gener-- 
ated  may  be  used  in  the  car  and  the  remainder,  if  any, 
pass  into  the  open  air. 

The  friction  of  the  track  brakeshoe  also  may  be 
adjusted  to  some  extent  through  the  angular  inclina- 
tion of  the  push  rods,  c.  This  would  throw  some  of  the 
weight  of  the  car  upon  the  track  shoes,  the  levers,  d, 
being  correspondingly  adjusted  to  reduce  the  wheel 
brakeshoe  pressure  in  proportion  as  the  weight  is  trans- 
ferred to  the  track  shoe.  The  current  declines  with  the 
speed  during  a  stop,  and  in  bad  weather,  when  the  con- 
dition of  the  rails  is  liable  to  be  accompanied  by  wheel 
sliding,  the  braking  force  operating  the  wheel  brake 
is  correspondingly  reduced,  so  that  the  force  of  appli- 
cation of  the  wheel  brakes  is  automatically  propor- 
tioned to  the  rail  friction  which  rotates  the  wheels.  If 
by  chance  the  wheels  should  slide  upon  the  rails,  the  in- 
terruption of  wheel  rotation  cuts  off  the  track-magnet 


BRAKES    AND    THEIR    OPERATION.  151 

current,  through  which  the  pressure  of  the  brakeshoes 
upon  the  wheel  is  instantly  relaxed,  and  rotation  of  the 
wheels  is  resumed  without  injury  or  serious  loss  of 
time. 

Straight  Air  Brakes.— The  straight  air-brake  sys- 
tem has  been  universally  adopted  as  the  standard  form 
of  power  brake  for  electrically  propelled  cars,  either 
when  operated  as  single  units  or  when  hauling  one  or 
two  trailers.  The  factors  which  have  led  to  its  uni- 
versal use  are: 

(1)  Positive  control,  (2)  Simplicity,  and  (3)  Ease 
of  manipulation.  All  of  these  features  are  possessed 
by  this  system  to  a  higher  degree  than  by  any  other. 

The  straight  air-brake  system  consists  essentially 
of  a  source  of  compressed  air,  a  brake  cylinder,  and  a 
simple  valve  under  the  direct  control  of  the  motorman, 
the  use  of  which  is  to  control  the  admission  and  exhaust 
of  the  compressed  air  to  and  from  the  brake  cylinder 
as  desired.  A  diagram  showing  the  connections  of  the 
different  parts  of  one  system  is  shown  in  Figure  129. 

This  straight  air-brake  equipment  consists  of  the 
following  parts,  as  indicated  by  numbering: 

1.  Electric  motor-driven  air  compressor. 

2.  Box  for  compressor. 

3.  Cage  for  supporting  box  and  compressor  under 
a  car. 

4.  Insulating  coupling. 

5.  Reservoir  for  storage  of  the  compressed  air. 

6.  Automatic  electric   governor. 

7.  Cover  for  governor. 

8.  Insulating  coupling. 

9.  Non-arcing  enclosed  fuse  to  protect  the  com- 
pressor motor. 

10.  Brake    cylinder  with   hollow   piston   rod   ar- 


152 


THE    MOTORMAX. 


Figure   129 — Parts   of   Straight   Air- Brake   System. 


BRAKES    AND    THEIR    OPERATION.  153 

ranged  to  allow  of  the  hand  brake  being  easily  applied 
through  the  same  lever  system. 

11.  Pressure  gauge. 

12.  Engineer's  valve  for  admitting  air  to,   and 
releasing  it  from,  the  brake  cylinder. 

13.  Handle  for  engineer's  valve. 

14.  Cut-out  cock  for  trailer  connection. 

15.  Hose  and  coupling  for  trailer. 


Figure  130 — Air-Compressor  Motor  in  Cradle. 

16.  Switch. 

17.  Whistle. 

18.  Independent  valve  for  whistle. 

19.  Brake  lever  rigging. 

20.  21.     Pipe  fittings. 

The  application  of  the  brakes  by  admission  of  com- 
pressed air  from  the  reservoir  to  the  brake  cylinder  is 
effected  by  opening  ports  in  an  operating  valve,  thereby 
causing  the  piston  in  the  cj'linder  to  move  outwardly, 
applying  the  brakes  with  a  greater  or  less  degree  of 
force,  depending  upon  the  size  of  the  port  that  is  tised, 
and  the  length  of  time  that  it  remains  open.  Thus  the 
motorman  is  able  to  apply  the  brakes  with  such  pres- 


154  THE    MOTORMAN. 

sure,  up  to  the  maximum,  and  in  as  small  a  space  of 
time  as  is  desired.  After  admitting  air  to  the  cylinder, 
if  the  handle  is  placed  in  the  position  where  all  ports 
are  closed,  the  air  already  admitted  to  the  brake  cylin- 
der is  Detained  there,  thus  holding  the  brakes  applied. 
A  further  movement  of  the  handle  to  the  release  posi- 


Figure  131 — Air  Compressor. 

tion  connects  the  brake  cylinder  with  the  atmosphere, 
permitting  the  air  to  escape,  thus  releasing  the  brakes. 
A  graduated  release  of  the  brake  may  be  obtained  by 
permitting  a  portion  of  the  air  in  the  cylinder  to  escape 
and  then  returning  the  handle  to  the  position  where  all 
ports  are  closed. 


BRAKES    AND    THEIR    OPERATION. 


155 


Air  Compressor. — The  air  compressor  is  directly 
mounted  on  two  oak  planks  supported  in  a  cradle  made 
of  Avrought-iron  bars.  The  cradle  is  suspended  beneath 
the  car  from  the  floor  beams,  as  shown  in  Figure  130. 

The  air  compressor  (Figure  131)  consists  of  two 
cylinders,  with  single-acting  pistons  connected  to  one 
crank  shaft  which  is  driven  by  an  electric  motor 
through  gears.  One  piston  compresses  air  while  the 


Figure    132 — Air   Compressor    Disassembled. 

other  draws  it  into  the  cylinder.  A  disassembled  view 
of  the  motor  compressor  is  given  in  Figure  132. 

Compressor  Governor. — The  current  that  is  used 
by  the  motor  driving  the  air  pump  is  controlled  by  an 
automatic  governor,  one  type  of  which  is  shown  in 
Figure  133. 

The  duty  of  the  governor  is  to  automatically  con- 
trol the  operation  of  the  air  Compressor  driven  by  its 


156  THE    MOTORMAN. 

motor,  stopping  it  when  the  desired  maximum  pressure 
is  reached,  and  starting  it  when  the  pressure  falls  be- 
low a  set  minimum.  The  difference  between  these  pres- 
sures is  usually  10  pounds.  It  does  this  by  automatic- 
ally making  and  breaking  the  electrical  circuit  to  the 
motor  as  the  pressure  falls  below  or  rises  above  the 
pressure  for  which  the  governor  is  set.  It  thus  fur- 
nishes a  steady  supply  of  air  for  the  use  of  the  motor- 
man  in  stopping  the  car. 

The  brake  cylinder  is  shown  in  Figure  134  in  con- 


Figure  133 — Oil- Break  Air-Compressor  Motor  Governor. 

nection  with  the  hand-brake  rigging  as  installed  on 
double-truck  cars.  The  reader  will  note  that  the  same 
system  of  levers  serves  for  both  air  and  hand  brakes. 

Motor-man's  Valves.— The  motorman's  operating 
valve  is  the  device  by  which  the  motorman  controls  the 
application  of  the  brakes  and  is  a  highly  important 
part  of  the  air-brake  equipment.  The  duty  which  the 
motorman's  valve  performs  is  to  connect  reservoir  pipe, 
train  pipe  and  exhaust  in  such  a  way  that  air  will  flow 
through  the  reservoir  pipe  into  the  train  pipe,  passing 
thence  to  the  brake  cylinder,  or  will  issue  from  the  train 


BKAKES    AND    THEIR    OPERATION. 


157 


pipe  to  atmosphere,  depending 
upon  whether  it  is  desired  to 
apply  or  to  release  the  brakes. 

The  appliance  essentially 
consists  of  a  sliding  or  rotating 
valve  with  ports  on  its  lower 
face  so  arranged  that  tin ., 
register  at  the  proper  times 
with  suitable  ports  in  the 
valve  seat  to  make  the  neces- 
sary connections  for  the  de- 
sired braking  application.  The 
valve  seat  contains  ports  which 
connect  with  the  main  reser- 
voir, brake  cylinder  and  at- 
mosphere, respectively. 

The  valve  is  manipulated 
by  turning  a  removable  handle 
fitted  to  the  end  of  the  valve 
stem  or  spindle ;  this  handle 
moves  through  an  arc  of  about 
120  degrees  in  turning  from 
release  position  at  the  extreme 
left  to  emergency  position  at 
the  extreme  right.  The  handle 
can  only  be  inserted  or  re- 
moved when  the  valve  is  in 
lap  position  and  all  ports  are 
blanked  so  that  there  is  no 
connection  whatever  between 
any  of  the  three  ports  in  the 
valve  seat.  When  the  handle 
is  removed  the  mechanism  is 
securely  safeguarded  by  a  pro- 


158  THE    MOTORMAN. 

tecting  shield,  which  prevents  meddlesome  persons 
from  getting  a  grip  on  the  operating  spindle  either 
with  the  hand  or  with  a  wrench. 

Figure  135  shows  a  top  view  of  one  style  of  valve 
and  has  indicated  on  it  the  various  positions  of  the 
operating  handle  for  the  different  stages  of  setting  and 
releasing  the  brakes. 

Operating    Instructions. — The    motorman    should 
thoroughly  familiarize  himself  with  the  air-brake  equip- 
ment so  that  he  may  obtain  the  full  advantage  of  the 
most  efficient  operation. 
He  should   discard  the 
notion  (if  he  happens  to 
be  unfamiliar  with  the 
details   of  the   appara- 
tus) that  the  air  brake 
is  difficult  and  intricate 
to  understand  in  its  de- 
tails, because  it  is  not.  -  «, 
Following  is  a  summary 
of  the  main  points  for             Fi9ure  135-vaive  Positions, 
his  guidance: 

1.  To  start    the    compressor,     close    the    canopy 
switch.     This  will  automatically  close  the  governor  so 
that  current  will  pass  from  trolley  to  ground  through 
the  motor,  thus  driving  the  compressor. 

2.  Should  the  compressor  refuse  to  work  under 
this  condition,  the  fuse  may  be  blown.     If  so,  do  not 
put  in  a  heavier  fuse  than  specified  for  the  size  of  the 
compressor.     If  the  fuse  is  in  order,  he  should  try  to 
locate  the  trouble,  or  should  report  the  matter  to  the 
proper  person. 

The  engineer's  valve  is  made  with  a  detachable 
handle  which  is  only  removable  in  what  is  known  as 


BRAKES    AND    THEIR    OPERATION.  159 

"lap  position,"  in  which  position  the  valve  is  neutral 
in  the  same  manner  as  the  main  controller  is  by  remov- 
ing the  reverse  handle. 

A  service  application  of  the  brakes  is  effected  by 
moving  the  handle  of  the  engineer's  valve  to  the  first 
notch  on  the  right.  As  soon  as  sufficient  pressure  is 
brought  against  the  wheels,  the  handle  may  be  moved 
back  into  lap  position,  whereby  the  brakes  remain  set 
at  that  pressure.  If  it  is  desired  to  increase  the  rate 
of  braking  the  above  operation  may  be  repeated.  By 
moving  back  the  lap  without  releasing,  the  handle  may 
be  removed  and  the  brake  released  from  the  other  end 
of  the  car.  ^ 

By  moving  the  handle  from  lap  position  to  the  first 
notch  on  the  left  a  slow  release  of  the  brakes  is  effected, 
which  release  may  be  checked  in  the  same  way  by  mov- 
ing the  handle  back  to  lap  position,  the  same  as  in 
service  applications  of  the  brakes. 

An  emergency  application  is  effected  by  moving 
the  handle  to  the  extreme  right.  This  opens  a  large 
port  between  reservoir  and  brake  cylinder,  giving  an 
immediate  full  reservoir  pressure  in  the  cylinder  and 
an  instantaneous  application  of  the  brakes. 

By  moving  the  handle  from  lap  position  to  the 
extreme  left  a  large  .port  is  opened  between  the  brake 
cylinder  and  atmosphere,  effecting  an  immediate  re- 
lease of  the  brakes. 

When  the  brakes  are  not  being  applied  or  released, 
the  handle  of  the  engineer's  valve  should  always  be  on 
the  first  notch  to  the  left,  or  that  of  slow  release. 

The  leverage  and  total  pressure  on  the  brake  cyl- 
inder is  so  proportioned  that  under  ordinary  circum- 
stances, with  a  dry  rail,  the  wheels  cannot  skid.  If  the 
rail  is  in  bad  condition  for  stopping,  the  leverage  and 


160  THE    MOTORMAN. 

pressure  being  the  same  as  under  normal  conditions, 
would  probably  skid  the  wheels,  if  the  brake  cylinder 
is  charged  with  the  full  pressure.  In  such  instances 
care  should  be  taken  not  to  slide  the  wheels  by  intro- 
ducing too  much  pressure  to  the  brake  cylinder.  If 
the  wheels  slide,  which  can  be  instantly  felt,  the  handle 
is  moved  over  to  slow  release,  letting  out  air  until  the 
wheels  again  revolve,  then  back  to  lap,  and  release 
again  just  before  the  car  comes  to  a  dead  stop.  This 
will  prevent  the  disagreeable  jar  which  follows  if  a 
car  comes  to  a  dead  stop  with  the  brakes  applied. 

The  quickest  stop  obtainable  is  made  by  applying 
to  the  wheels,  throughout  the  stop,  the  greatest  pres- 
sure possible  without  causing  them  to  slide  on  the 
rails,  and  the  higher  the  speed  the  greater  the  pres- 
sure that  may  be  applied  without  danger  of  sliding. 
Thus  it  is  evident  that  in  order  to  make  a  quick  stop, 
full  pressure  should  be  applied  at  once,  and  gradually 
released  as  the  speed  falls;  this  method  will  also  give 
a  smooth  stop,  as  the  rapid  reduction  of  speed  at  the 
end  of  the  stop,  which  throws  passengers,  is  avoided. 
Therefore,  in  making  a  service  stop,  admit  25  or  30 
pounds  of  air  pressure  to  the  brake  cylinder  quickly 
at  the  beginning  of  the  stop  by  partially  opening  the 
large  port,  and  release  it  little  by  little  as  the  speed 
drops,  retaining  about  10  pounds  in  the  cylinder  till 
the  car  stops.  A  little  experience  will  show  the  dis- 
tance required  in  which  to  make  a  stop  from  a  given 
speed  so  that  all  stops  will  be  made  quickly,  smoothly 
and  with  but  one  application  of  the  brake. 

A  succession  of  applications  and  releases  while 
making  a  stop  imparts  a  very  disagreeable  motion  to 
the  ear,  is  most  wasteful  of  compressed  air,  and  is  bad 
practice  in  every  respect.  For  the  emergency  stop 


BRAKES    AND    THEIR    OPERATION.  161 

admit  full  pressure  (about  60  pounds)  immediately, 
without  even  waiting  till  the  controller  is  turned  off; 
then  apply  sand  and  release  a  little  of  the  pressure  as 
the  speed  drops. 

Upon  receiving  the  signal  to  go  ahead,  turn  the 
handle  to  the  release  position  before  turning  on  the 
electric  power.  When  descending  a  grade  a  beginner 
generally  makes  the  mistake  of  putting  the  brake  on 
too  hard  at  the  start;  it  cannot  be  expected  that  the 
instant  the  brake  is  applied  the  car  Will  take  the  speed 
desired;  make  an  easy  application  at  first,  hold  the 
handle  at  "lap"  and  give  the  car  time  to  feel  the  effect 
of  the  brake,  then,  if  the  speed  is  still  too  high,  let  in  a 
little  more  air;  repeat  the  operation  as  often  as  neces- 
sary until  off  the  grade,  in  case  it  is  a  long  one. 

When  leaving  a  car,  always  set  up  the  hand  brake, 
as  some  one  might  tamper  with  the  cut-out  cocks. 
Before  starting  from  the  car  barn,  be  sure  all  cocks  are 
properly  set  and  that  there  is  a  good  supply  of  air  in 
the  reservoir.  Insert  the  handle  in  its  socket  in  the 
operating  valve  and  throw  it  around  to  emergency, 
then  back  to  release,  to  see  that  it  works  freely.  Try 
the  air  brake  both  in  "service"  and  "emergency"  to 
make  sure  that  it  has  not  been  left  improperly  con- 
nected, etc.  After  this  trial,  and  as  long  as  proper 
pressure  is  maintained,  the  brake  may  be  relied  upon  to 
perform  its  duty. 

Care  must  be  taken  in  making  up  trains,  that  all 
hose  couplings  are  thoroughly  united  so  that  the  air 
will  apply  throughout  the  entire  train.  All  the  cut-out 
cocks  must  be  opened,  except  those  on  the  rear  of  the 
last  car  and  on  the  front  of  the  motor  car,  which  must 
be  closed.  In  uncoupling  the  cars  close  the  cocks  and 
disconnect  the  hose  before  pulling  the  drawbar  pin. 


162 


THE    MOTORMAN. 


BRAKES    AND    THEIR    OPERATION.  163 

The  air  brake  is  essentially  a  labor-saving  device 
for  the  motorman,  and  it  is  scarcely  necessary  to  ask 
for  his  co-operation  in  the  use  and  care  of  it.  Its  suc- 
cess and  general  adoption  for  fast  and  heavy  street 
railway  service  depend  very  much  on  his  interesting 
himself  in  its  use,  and  having  an  intelligent  under- 
standing of  the  functions  of  the  various  parts,  that  he 
may  readily  notice  when  anything  about  them  is  not 
working  properly,  and  report  the  trouble  before  it  be- 
comes serious.  Like  the  other  apparatus  of  a  street 
car,  the  air  brake  will  not  operate  indefinitely  without 
attention,  and  the  old  proverb  of  "a  stitch  in  time  saves 
nine"  applies  in  this  case  as  in  all  others. 

Emergency  Features. — The  emergency  straight  air- 
brake system  for  the  combined  operation  of  single  cars 
and  short  trains  has  been  developed  by  the  air-brake 
manufacturers.  The  apparatus  required  does  not  dif- 
fer greatly  from  that  of  a  straight  air-brake  system. 
The  application  and  release  of  brakes,  except  in  cases 
of  emergency,  is  made  in  the  same  way,  that  is  to  say, 
air  is  admitted  or  exhausted  from  the  brake  cylinder 
directly  through  the  motorman 's  valve.  Two  lines  of 
piping,  called  the  reservoir  and  the  train  lines,  run 
through  the  train  connecting  the  motorman 's  valve 
and  emergency  valves.  Figures  136  and  137  illustrate 
the  system  of  piping  connections  used  in  one  manu- 
facturer's type  of  emergency  straight  air-brake  equip- 
ment. Figure  136  shows  the  equipment  for  motor  cars 
and  Figure  137  shows  the  equipment  for  trail  cars. 

The  desirable  feature  of  this  system  is  obtained  by 
the  use  of  the  emergency  valve.  The  brakes  are  ap- 
plied automatically  in  case  the  reservoir  line  pressure 
is  suddenly  reduced,  as  would  happen  in  an  emergency 


164 


THE    MOTORMAN. 


BRAKES    AND    THEIR    OPERATION.  165 

application  or  if  the  train  parts  or  a  coupling  hose 
should  burst. 

With  the  straight  air-brake  system  the  train  line 
is  not  always  under  pressure,  and  the  uncoupling  of 
the  hose  connections  between  cars  is  not  an  uncommon 
accident  and  leaves  the  trail  cars  without  air  brakes. 
With  the  emergency  straight  air-brake  system,  a  break 
in  the  train  line  has  no  effect  on  the  emergency  valve, 
which  still  can  be  operated  as  ordinarily  by  throwing 
the  motorman's  valve  handle  to  the  emergency  position. 

Automatic  Air  Brakes.— The  automatic  air  brake, 
first  designed  for  steam  railway  trains,  is  now  coming 
into  general  use  for  those  electric  railways  that  operate 
more  than  two  cars  in  one  train. 

The  essential  difference  between  the  automatic 
and  straight-air  traction  brake  systems  is  that  in  the 
latter  air  is  admitted  to  the  train  pipe  to  apply  the 
brakes  and  allowed  to  escape  from  it  to  release  them ; 
whereas,  in  the  automatic  system,  air  is  allowed  to  es- 
cape from  the  train  pipe  in  order  to  apply  the  brakes, 
and  is  admitted  to  it  again  to  release  them.  With  the 
straight-air  equipment  the  train  pipe  is  never  under 
pressure  except  during  an  application  of  the  brakes, 
whereas  the  automatic  train  pipe  is  under  pressure,  ex- 
cept in  emergency  applications,  and  this  pressure  is 
greatest  when  the  brakes  are  released. 

Each  brake  cylinder  in  the  automatic  system  is 
provided  with  its  own  reservoir,  called  the  auxiliary 
reservoir,  in  which  air  is  stored  for  use  in  this  cylinder 
only.  The  reservoir. which  receives  the  compressed  air 
directly  from  the  compressor  is,  in  this  case,  called 
the  main  reservoir,  and  furnishes  the  air  to  charge  the 
train  pipe  and  auxiliary  reservoirs,  and  to  release  the 
brakes. 


166 


THE    MOTORMAN. 


The  connection 
between  each 
brake  cylinder  and 
its  auxiliary  reser- 
voir and  the  train 
pipe  is  made 
through  a  triple 
valve  in  a  manner 
to  be  explained 
presently. 

Figure  138  il- 
lustrates the  es- 
sential parts  of  the 
automatic  brake 
system  and  their 
relative  location, 
as  usually  applied 
to  trains  of  two  or 
more  cars. 

The  opera- 
tions  of  the  brake 
are  controlled  by 
the  triple  valve,  the 
primary  parts  of 
which  are  a  piston 
and  slide  valve.  A 
moderate  reduc- 
tion of  air  pres- 
sure in  the  train 
pipe  causes  the 
greater  pressure 
remaining  stored 
in  the  auxiliary 
reservoir  to  force 


BRAKES    AND    THEIR    OPERATION.  167 

the  piston  and  its  slide  valve  to  a  position  which  allows 
the  air  in  the  auxiliary  reservoir  to  pass  into  the  brake 
cylinder  and  apply  the  brake.  A  sudden  or  vio- 
lent reduction  of  the  air  in  the  train  pipe  pro- 
duces the  same  effect,  but,  in  addition  (if  a  quick- 
action  triple  valve),  it  causes  supplemental  valves 
to  be  opened,  permitting  the  air  from  the  train 
lent  reduction  of  the  air  in  the  train  pipe  pro- 
ducing a  brake-cylinder  pressure  about  20  per  cent 
greater  than  that  derived  from  the  auxiliary  reservoir 
alone,  and  producing  a  practically  instantaneous  appli- 
cation of  the  brakes  throughout  the  train.  When  the 
pressure  in  the  train  pipe  is  subsequently  increased 
above  that  remaining  in  the  auxiliary  reservoir,  the 
piston  and  slide  valve  are  forced  in  the  opposite  direc- 
tion to  their  normal  positions,  thereby  restoring  com- 
munication between  the  train  pipe  and  the  auxiliary 
reservoir  and  permitting  the  air  in  the  brake  cylinder 
to  escape  to  the  atmosphere  through  the  triple-valve 
exhaust  port,  thus  releasing  the  brakes,  and  at  the 
same  time  recharging  the  auxiliary  reservoirs. 

When  the  motorman  wishes  to  apply  the  brakes, 
he  moves  the  handle  of  the  motorman 's  brake  valve  to 
the  right,  which  cuts  off  communication  with  the  main 
reservoir  and  permits  a  portion  of  the  air  in  the  train 
pipe  to  escape;  to  release  the  brakes,  he  moves  the 
handle  to  the  extreme  left,  which  allows  air  to  flow 
from  the  main  reservoir  into  the  train  pipe,  restoring 
the  pressure  therein. 

A  device  called  the  conductor's  valve  may  be 
placed  on  each  car,  to  which  is  attached  a  cord  that 
runs  throughout  the  length  of  the  car.  In  case  of  acci- 
dent, by  pulling  this  cord,  the  valve  is  opened  and  dis- 
charges air  from  the  train  pipe,  applying  the  brakes. 


168  THE    MOTORMAN. 

When  the  train  has  been  brought  to  a  full  stop  in  this 
manner  the  valve  must  be  closed. 

Should  a  train  break  in  two,  the  escape  of  the  air 
in  the  train  pipe  applies  the  brakes  automatically  to 
both  sections.  The  brakes  are  also  automatically  ap- 
plied through  the  bursting  of  a  hose  or  pipe.  In  fact, 
any  material  reduction  of  pressure  in  the  train  pipe  ap- 
plies the  brakes,  which  is  the  characteristic  feature  of 
the  automatic  brake. 

An  angle  cock  is  placed  in  the  train  pipe  at  each 
end  of  every  car,  which  must  be  closed  before  separat- 
ing the  couplings,  to  prevent  an  application  of  the 
brakes.  A  cut-out  cock  is  also  placed  in  the  cross- 
over pipe  leading  from  the  train  pipe  to  the  quick- 
action  triple  valve,  and  also  in  the  train  pipe  near  the 
motorman's  brake  valve,  within  convenient  reach  of 
the  motorman.  The  former  is  for  the  purpose  of  cut- 
ting out,  or  rendering  inoperative,  the  brake  appara- 
tus upon  a  car,  if  for  any  reason  it  should  become  dis- 
abled; the  latter  is  for  cutting  out  the  motorman's 
brake  valve  upon  all  motor-cars  except  the  first,  in 
case  two  or  more  are  attached  to  the  same  train. 

Operation  of  Automatic  Air  Brakes. — After  making 
up  a  train  the  brakes  should  always  be  tested  in  the 
following  manner:  With  the  brake-valve  handle  in 
the  running  position,  charge  the  train  line  and  auxil- 
iary reservoirs ;  to  determine  when  the  charging  is  com- 
plete, place  the  brake-valve  handle  in  lap  position  and 
when  everything  is  charged,  the  black  hand  of  the 
duplex  gauge  will  not  fall.  The  motorman  should 
then  apply  the  brakes  by  moving  the  handle  of  the 
brake  valve  to  the  service  application  notch  until  a  re- 
duction of  10  pounds  has  been  made  in  the  tramline. 
Then,  after  placing  the  brake  valve  on  lap,  the  motor- 
man should  remove  the  handle,  and,  carrying  it  with 


BRAKES    AND    THEIR    OPERATION.  169 

him,  proceed  along  the  length  of  the  train  and  see  that 
the  cylinder  piston  of  every  car  has  moved  out  such  a 
distance  as  to  indicate  that  the  brakes  are  properly 
applied  on  all  cars  of  the  train.  He  should  then  re- 
lease the  brakes  from  the  last  cab  at  the  rear  end ;  then 
again  remove  the  handle  and  return  to  the  front  end, 
examining  all  cylinder  pistons.  He  should  be  careful 
to  see  that  they  have  moved  back  to  full  release,  thus 
indicating  that  all  brakeshoes  hang  free. 

For  any  purpose  except  testing  brakes  or  making 
an  emergency  application,  the  first  reduction  in  train- 
line  pressure  should  be  from  five  to  seven  pounds. 
After  the  first  five  to  seven  pound  reduction,  the  best 
results  are  obtained  by  not  using  more  than  three  or 
four  pounds  at  any  one  reduction ;  this,  however,  must 
be  governed  entirely  by  the  circumstances.  As  from 
13  to  15  pounds  reduction  in  train-line  pressure  causes 
an  equalization  of  auxiliary-reservoir  and  brake-cylin- 
der pressures,  when  making  a  service  application,  thus 
fully  applying  the  brake,  a  further  reduction  in  train 
line  is  simply  a  waste  of  air.  The  results  of  such  a 
waste  are  that  the  brakes  are  slower  in  releasing ;  they 
fail  to  release  simultaneously;  they  cause  shocks  to  the 
train  upon  stopping;  and  they  seriously  overtax  the 
compressor. 

In  making  the  ordinary  service  stop,  two  applica- 
tions generally  should  be  made.  The  use  of  two  ap- 
plications instead  of  one  in  making  a  service  stop  is 
better  because  this  method  of  handling  the  brakes 
quickly  brings  the  train  down  from  a  high  to  a  low 
speed,  is  a  safeguard  against  skidding  of  wheels,  insures 
greater  accuracy  in  making  stops  and  permits  the 
train  to  be  brought  to  a  standstill  with  a  light  reduc- 
tion of  pressure  on  the  second  application. 

In  releasing  the  brakes  after  making  an  applica- 


170  THE    MOTORMAN. 

tion  in  a  service  stop  with  the  intention  of  immediately 
making  a  second  application,  the  brake-valve  handle 
should  be  moved  to  the  full  release  and  at  once  returned 
to  the  lap  position.  In  making  ordinary  station  stops  a 
partial  release  of  the  brakes  should  be  made  at  a  suffi- 
cient time  before  the  train  comes  to  a  standstill  to  avoid 
the  backward  lurch.  Immediately  upon  the  train  com- 
ing to  a  standstill  move  the  handle  to  full  release  posi- 
tion until  the  train  line  is  charged  to  maximum  pres- 
sure, then  bring  it  back  to  running  position.  This  also 
applies  at  all  other  times  when  the  brakes  have  been 
applied  and  full  release  is  desired. 

In  making  full  release  of  the  brakes  the  brake- 
valve  handle  invariably  should  be  moved  to  the  full- 
release  position.  If  the  brakes  release  after  a  service 
application,  examine  all  the  brake  valves  in  the  train 
until  the  trouble  is  located.  Either  a  brake  valve  has 
not  been  fully  lapped  or  has  a  rotary  valve  leaking. 

In  case  of  emergency  when  it  is  essential  to  stop 
the  train  in  the  shortest  possible  distance,  the  handle 
should  be  thrown  to  the  full  emergency  position  and 
left  there  until  the  train  has  come  to  a  stop,  or  the 
danger  is  passed.  If  the  motorman  has  the  brake  par- 
tially applied  in  service  application,  and  should  be  sud- 
denly flagged,  he  should  put  the  valve  handle  in  the 
emergency  position  and  leave  it  there  until  stopped. 
As  a  last  resort  to  prevent  collision  or  to  save  life,  a 
motorman  may  reverse  the  motors.  The  reverse  handle 
should  be  thrown  into  opposite  direction  and  the  con- 
troller handle  moved  to  the  second  notch,  which  notch 
is  usually  found  to  have  the  greatest  retarding  effect. 
Motors  may  also  be  reversed  in  the  event  of  the  brakes 
being  inoperative,  but  in  ordinary  service  conditions 
motormen  must  never  reverse  the  motors. 


BRAKES    AND    THEIR    OPERATION.  171 

In  case  the  brakes  apply  suddenly  without  appar- 
ent cause,  the  motorman  should  place  the  brake-valve 
handle  in  lap  position  until  a  signal  is  given  to  release 
the  brakes.  This  prevents  the  escape  of  main  reser- 
voir pressure,  thereby  providing  for  a  prompt  release 
of  the  brakes. 

A  burst  train-line  hose  or  train  pipe,  or  the 
breaking  in  two  of  the  train,  will  apply  the  brakes;  in 
that  event  close  the  train-pipe  cock  immediately  ahead 
of  the  break  and  release  the  brakes  to  the  rear  of  it  by 
opening  the  release  valves  in  the  auxiliary  reservoirs. 
The  brakes  ahead  of  the  closed  train-pipe  cock  can  be 
released  by  the  motorman  and  operated  to  handle  the 
train  until  the  fractured  hose  can  be  replaced. 

In  setting  off  cars  the  train-pipe  cocks  should  be 
clos<  d  first  and  the  hose  parted  by  hand  and  hung  up 
properly ;  never  leave  the  hose  to  be  jerked  apart  by  the 
separating  of  the  cars.  Before  setting  the  hand  brake 
on  the  set-off  car  make  sure  that  the  air  brake  has  been 
released.  The  foundation  brake  rigging  of  some  cars 
is  so  constructed  that  the  hand  and  power  brakes  pull 
against  each  other,  in  which  case  if  the  hand  brake  is 
set  up  with  the  air  brake  applied,  the  leaking  off  of  the 
latter  would  release  the  brakes. 

Storage  Air  Brakes. — One  system  uses  compressed 
air  which  is  stored  in  tanks,  but  is  not  compressed  upon 
the  car,  as  previously  described.  At  the  car  barn 
or  other  central  point  a  storage  tank  is  provided 
containing  compressed  air.  The  tanks  on  the  car 
are  filled  from  this  storage  tank  in  a  few  moments. 
A  tank  capacity  is  provided  on  the  car  to  be  sufficient 
for  from  300  to  500  stops,  or  several  round  trips  over 
an  ordinary  city  route.  The  initial  pressure  in  the 
main  reservoir  on  the  car  is  usually  300  pounds  per 


172  THE    MOTORMAN. 

square  inch ;  by  a  reducing  valve  this  is  lowered  to  50 
pounds  or  less,  according  to  the  speed  and  weight  of 
the  cars.  At  this  pressure  the  air  enters  the  auxiliary 
reservoirs  on  the  cars.  From  the  auxiliary  reservoir  to 
the  brake  cylinder  the  air  is  controlled  by  the  en- 
gineer's valve.  The  brake  cylinder  is  provided  with 
two  pistons  so  adjusted  as  to  be  pressed  toward  each 
other  through  the  agency  of  a  spring,  or  other  similar 
means.  The  motorman's  valve  provides  for  connecting 
the  air  supply  or  reservoir  to  the  space  between  the 
pistons  whereby  the  pistons  may  be  separated  against 
the  tension  of  the  spring  to  apply  the  brake  when  it  is 
desired. 

To  release  the  brake  a  controlling  valve  is  operated 
to  cut  off  the  space  between  the  pistons  from  the  air 
supply  reservoir,  and  to  connect  it  with  the  air  space 
of  the  cylinder  behind  the  pistons;  thus  the  pressure 
on  the  opposite  side  of  the  piston  is  equalized  and  the 
springs  permitted  to  return  to  their  normal  positions. 

The  storage  air  brakes  are  operated  in  practically 
the  same  way  as  other  straight  air  brakes. 

Hints  on  Handling  Brakes.— The  description  of  the 
brake  mechanisms  has  been  given  more  particularly  for 
those  motormen  operating  cars  on  the  small  country 
roads  where  frequently  they  are  called  upon  to  attend 
to  such  mechanical  matters.  In  large  cities  and  on  large 
roads  special  inspectors  are  provided,  and  the  author 
wishes  to  impress  especially  on  those  motormen  who 
have  inventive  faculties,  or  imagine  they  have,  or  those 
who  like  to  do  tinkering,  that  they  should  touch  abso- 
lutely nothing  about  the  car  equipment  unless  ordered 
by  the  road  officers  or  regulations  to  do  so.  The  com- 
pany cannot  afford  to  have  a  man  experiment  with  its 
cars,  especially  when  mechanics  are  employed  to  attend 


BRAKES    AND    THEIR    OPERATION.  173 

to  all  irregularities  on  the  car  or  truck.  Inasmuch  as 
this  book  is  intended  to  tell  a  man  how  he  should 
qualify  himself  for  the  position,  it  must  not  only  tell 
him  how  to  get  a  position,  but  also  how  to  keep  it. 
However  much  a  man  might  desire  to  fix  his  car,  it  is 
not  worth  while  to  risk  his  position  if  he  acts  against 
the  rules  of  the  company  in  doing  so. 

While  starting  a  car  from  the  barn  try  the  brakes, 
to  see  if  they  are  right.  Always  be  sure  that  the 
brakes  are  fully  off  before  starting  the  controller.  On 
grades  it  will  be  necessary  to  start  the  controller  the 
instant  the  brake  is  released.  There  is  usually  some 
slack  in  the  brake  chain  with  hand  brakes  unless  the 
shop  men  keep  them  closely  adjusted. 

It  should  be  the  constant  effort  of  the  motorman 
to  avoid  locking  the  wheels  so  that  they  slide  or  skid 
along  the  rail.  There  are  two  good  reasons  for  this. 
In  the  first  place,  the  instant  the  wheels  begin  to  slide 
on  the  rails  the  braking  or  retarding  force  is  reduced, 
or,  what  is  the  same,  the  motorman  loses  more  than 
half  his  retarding  power.  This  has  been  fully  proved 
by  experiment  and  by  experience.  In  the  second 
place,  there  is  danger  that  by  this  sliding  along  the  rails 
flat  places  will  be  worn  on  the  wheels  and  rapidly 
will  pound  with  every  turn  of  the  wheels  and  quickly 
grow  worse,  so  that  the  noise  becomes  unbearable  to  the 
public  and  the  wheels  must  be  turned  down  at  consid- 
erable expense  or  thrown  away.  A  flat  wheel  on  a  car, 
therefore,  is  no  credit  to  a  motorman,  and  on  some 
roads  the  penalty  for  a  flat  wheel  is  suspension.  It  is 
often  hard  to  avoid  sliding  the  wheels  when  there  is 
sleet  or  mud  on  the  rails,  but  this  should  be  remembered 
above  all:  never  turn  on  sand  after  the  wheels  have 
commenced  to  slide  without  first  letting  up  on  the 


174  THE    MOTORMAN. 

brakes  so  that  the  wheels  can  turn.  The  safer  plan 
when  stopping  on  a  slippery  rail  is  to  apply  sand  at 
the  same  time  the  brakes  are  applied.  Remember  that 
the  ear  can  not  be  stopped  so  quickly  by  sliding  the 
wheels  as  by  putting  on  the  brakes  firmly  without  slid- 
ing them.  In  coining  to  a  steep  down  grade  be  sure 
to  slow  up  before  reaching  the  incline  and  set  the 
brakes  gradually.  If  the  wheels  get  to  sliding  on  the 
grade  loosen  up  on  the  brakes  until  they  begin  to  turn 
again.  Cars  have  run  away  down  hills  because  motor- 
men  have  lost  their  heads  or  failed  to  know  and  re- 
member this  point. 

The  wear  or  lasting  qualities  of  the  brakeshoes 
and  the  power  taken  from  the  power  plant  by  a  motor- 
man  to  run  a  car  depend  to  a  considerable  extent  on 
his  proper  judgment  of  time  and  distance.  The  less 
he  absorbs  the  stored  energy  with  the  brake  the 
smaller  will  be  the  wear  on  brakeshoes  and  car  wheels 
and  the  smaller  the  power  taken. 

It  is  not  a  good  plan  to  make  gradual  stops  by 
applying  the  brakes  lightly  a  long  distance  back  of 
where  you  want  to  stop,  as  you  lose  time  in  getting 
over  the  road  in  this  way  and  require  more  power  in 
making  up  for  it.  Let  the  car  drift  with  brake  en- 
tirely off  until  a  short  distance  from  the  stopping 
place,  and  then  apply  them  hard  enough  to  make  a 
comparatively  short  stop  without  sliding  the  wheels 
or  making  it  uncomfortable  for  the  passengers. 


CHAPTER  XI. 


HOW    TO     REMEDY    TROUBLES. 

On  many  large  roads  the  motormen  are  expected 
to  do  nothing  beyond  operating  their  ears,  and  when- 
ever trouble  occurs  to  a  car  on  the  road  it  is  pushed  in 
by  the  next  and  the  repair  men  at  the  barn  attend  to 
the  repairing.  A  motorman  should,  of  course,  always 
abide  by  the  rules  of  his  company,  and  if  it  forbids 
the  opening  of  motors  or  controllers  by  motormen  the 
author  does  not  mean  these  instructions  to  interfere  in 
any  way  with  rules  which  may  seem  necessary  to  the 
officers  of  large  systems  where  the  motormen  are  not 
all  well  posted  and  where  inspectors  are  employed 
whose  special  work  it  is  to  remedy  slight  troubles  and 
where  mischief  may  be  done  by  the  tampering  of  those 
who  do  not  understand  the  apparatus.  Nevertheless, 
there  are  many  small  roads  where  a  knowledge  of  how 
to  remedy  troubles  is  needed,  and  even  on  the  large 
roads -mentioned  the  man  who  understands  his  car  can 
save  many  delays  if  he  knows  how  to  report  troubles 
intelligently. 

In  enumerating  many  of  the  troubles  to  which  the 
cars  and  motors  are  subject  and  giving  instructions 
for  their  temporary  remedy,  the  author  wishes  to  place 
in  the  hands  of  the  motorman  facts  and  means  which 


176  THE    MOTORMAN. 

are  helpful  for  such  an  occasion.  However,  no  one 
should  think  that,  without  practical  experience,  by 
simply  reading  these  lines,  he  can  manage  a  car  as 
well  as  a  man  who  has  been  operating  one  for  years. 
Practical  experience  is  absolutely  necessary,  but  in 
connection  with  it  this  chapter  will  be  very  helpful 
to  the  motorman. 

A  great  deal  must  be  learned  by  actual  experience, 
and  success  in  economical  operation  on  a  car  line  de- 
pends partly  on  the  watchfulness  of  the  motorman. 
While  operating  his  controller  he  can  readily  detect 
irregularities,  first,  by  the  way  the  motors  take  the 
current  when  the  controller  is  operated,  and  secondly 
when  the  car  is  under  way,  by  the  sound  of  the  motors. 

The  economy  which  can  thus  be  accomplished  lies 
in  the  fact  that  loose  bolts,  a  loose  connection  and  the 
like  are  easily  tightened.  These  are  small  troubles, 
caused  by  constant  jarring  of  the  car,  which  are  easily 
attended  to.  However,  if  the  car  is  not  watched  bolts 
will  be  lost,  bearings  will  come  loose,  the  armature  re- 
volving at  a  high  rate  of  speed  may  be  rubbing  against 
the  field  magnet  poles,  or  a  wire  working  out  of  its 
connection  may  cause  a  short  circuit  and  blow  the  fuse, 
etc.  It  will  be  readily  seen  that  these  small  troubles, 
if  not  attended  to  in  time,  are  the  causes  of  others  far 
more  serious,  yet  a  turn  of  the  wrench  or  the  screw- 
driver in  proper  time  may  easily  prevent  such  troubles 
on  the  road.  The  well-known  rule,  "a  stitch  in  time 
saves  nine,"  should  be  remembered  at  all  times,  and 
besides  this  one:  "cleanliness  is  next  to  godliness." 
Keep  the  motors,  connections  and  contact  terminals 
clean  and  dry.  Before  working  around  the  electrical 
apparatus  pull  off  the  trolley  and  open  the  overhead 
switch. 


HOW  TO  REMEDY  TROUBLES.        177 

Failure  of  the  Car  to  Start.— If  the  car  fails  to 
start  when  the  controller  is  "on"  and  both  overhead 
switches  are  closed,  the  trouble  is  due  to  an  open  cir- 
cuit, and  probably  to  one  of  the  following  causes : 

1.  The  fuse  may  have  blown  or  melted.   Open  an 
overhead  switch  or  pull  off  the  trolley  and  put  in  a 
new  fuse,  removing  the  burned  ends  from  under  the 
binding  posts  before  doing  so.     Never  put  in  a  heavier 
fuse  than  that  specified  by  the  company,  as  it  might 
result  in  damage  to  the  equipment  by  allowing  too 
large  a  current  to  flow.     The  fuse  may  blow  because 
of  some  trouble  on  the  car,  as  will  be  explained  a 
little  further  on. 

2.  On  a  dry  summer  day,  when  there  is  much  fine 
dust  on  the  track,  it  happens  that  the  car  wheels  do 
not  make  proper  contact  with  the  rail  and  the  car  fails 
to  start.     In  such  a  case  try  to  establish  contact  by 
rocking  the  car  body.     Should  this  fail  to  work,  the 
conductor  should  take  the  switch  bar  or  a  piece  of 
wire  and,  holding  one  end  firmly  on  a  clean  place  on 
the  rail,  hold  the  other  against  the  wheel  or  truck. 
This  will   make   temporary   connection   until    the   car 
has  started.     The  conductor  should  be  sure  to  make 
his  rail  contact  first  and  keep  it  firm  during  this  oper- 
ation or  he  may  receive  a  shock. 

3.  If  the  track  conditions  apparently  are  good,  it 
may  be  that  the  car  stands  on  a  piece  of  dead  rail,  a 
piece  of  rail  on  which  the  bonding  has  become  de- 
stroyed.    In  that  case  the  car  conductor  would  have 
to  go  to  the  next  rail  section  with  a  piece  of  wire  to 
connect  the  two  rails  and  then  order  the  motorman 
to  start  his  car. 

4.  A  brush  or  two  may  not  have  been  placed,  or, 
if  placed,  may  fit  too  tightly  in  the  brush  holder,  so 


178  THE    MOTORMAN. 

that  the  springs  do  not  establish  contact  between  the 
brush  and  the  commutator.  If  this  is  the  case,  remove 
the  brushes  and  sandpaper  them  until  they  go  into 
the  brush  holder  easily. 

5.  The  contact  fingers  on  a  controller  are  rough, 
burnt,  and  perhaps  bent  so  that  the  drum  cannot  make 
contact.     It  may  also  be  due  to  wear  on  both  the  con- 
tact surfaces  of  the  drum  and  the  finger,  which  may 
have  been  burnt  and  worn  away  to  such  an  extent  that 
contact  is  not  established  when  the  controller  handle 
is  placed  in  the  first  notch.     Try  to  smooth  the  burnt 
surface  with  sandpaper  and  bend  the  fingers  or  con- 
tacts into  their  proper  position.    Should  this  fail,  then 
operate  the  car  with  the   other  controller.      In  this 
case  the  conductor  should  be  on  the  front  platform 
to  handle  the  brake  and  give  orders    to    the    motor- 
man  when  to  start  and  stop,  as  the  occasion  requires. 
Under  these  conditions  the  car  should  never  be  allowed 
to  travel  at  a  high  speed. 

6.  A  loose  or  broken  cable  connection.     This  can 
be  located  and  placed  and  fastened  in  its  position.     It 
is,  in  most  instances,  a  cable  connected  to  one  of  the 
motors,  rheostat  or  lightning  arrester,  and  very  sel- 
dom in  the  controller  stand. 

7.  A  burnt  rheostat.    A  rheostat  may  have  re- 
ceived too  great  a  current  for  some  time  and  the  first 
contact  terminal  may  be  broken.     In  such  a  case,  if 
temporary  connection   cannot   conveniently  be   estab- 
lished, the  car  will  not  start  at  the  first  notch,  but  at 
the  second  it  will  start  with  a  jerk. 

8.  If  the  car  refuses  to  start  on  the  first  contact, 
but  starts   all  right  on  the  second  and  acts  normal 
thereafter,  then  there  is  an  open  circuit  in  the  rheostat, 
either  internally,  or  the  first  cable  connection  is  broken. 


HOW  TO  REMEDY  TROUBLES.         179 

It  may  also  be  due  to  a  worn  controller  and  the  con- 
tacts may  be  blistered  or  burnt.  Move  the  controller 
handle  slightly  beyond  the  notch  or  go  direct  to  the 
second  notch. 

9.  The  field  coil  of  a  motor  may  be  grounded  so 
that  the  fuse  blows  whenever  the  current  is  turned  on. 
Cut  out  the  faulty  motor,  as  explained  in  Chapter  VII. 

10.  Armature    or    commutator    grounded.       Cut 
out  the  motor  as  in  case  9. 

11.  The  lightning  arrester  is  grounded  by  dirt 
between  the  discharge  points.     Remove  the  dirt,  as  the 
fuse  will  blow  as  long  as  the  trouble  exists.     Should 
this  not  be  possible  then  disconnect  the  lightning  ar- 
rester, ground  wire,  insert  fuse  and  go  ahead.     The 
trouble  lies  in  the  arrester. 

12.  The  car  starts  and  the  fuse  may  blow.     This 
may  be  due  to  a  heavy  load  and  the  fuse  not  being 
securely  fastened  to  its  terminals.     The  screws  hold- 
ing the  terminals  of  the  fuse  should  be  tight,  because 
loose  contact  at  these  points  will  cause  heating  and  an 
increased  resistance,   and,  in   consequence,   a   quicker 
burning  of  the  fuse. 

13.  Case  12  also  may  happen  with  comparatively 
few  passengers.   The  load  may  be  caused  artificially  by 
having  the  brakes   partially  set  or  by  dirt  clogging 
the  space  between  the  brakeshoes  and  car  wheels.    Re- 
move the  obstruction  between  brakeshoes,  then  insert 
the  fuse. 

14.  In  car  equipments,  with  motors  permanently 
in  parallel,  the  fuse  will  blow  if  a  field  or  armature  is 
short-circuited.    Proceed  as  in  case  9. 

There  are  also  other  irregularities  which  may  oc- 
cur, as  follows: 


180  THE    MOTORMAN. 

15.  Some  cables  form  a  short  circuit  either  under 
the  seat  or  below  the  controller,  due  to  dampness,  dirt, 
damaged  insulation,  etc.     This  can  readily  be  detected 
by  the  smell  of  burnt  rubber.  Having  found  the  place, 
first  open  the  overhead  switch,  then  proceed  to  wrap 
rubber  tape  around  the  bare  place.     If  this  is  not  on 
hand,  use  some  dry  cotton  or  woolen  rag  torn  into  a 
narrow  band  or  else  dry  string.     If  the  wires  cannot 
be  separated  far  enough,  place  some  short  pieces  of 
dry  wood  between  them  and  then  tie  them  together. 

16.  The  car  starts  and  after  the  controller  reaches 
a  certain  point  the  fuse  blows.     One  armature  or  a 
field  is  short-circuited.     Cut  out  the  faulty  motor  and 
go  on  with  the  other. 

17.  The  car  starts,  stops  and  starts  again.    This 
may  be  caused  by  a  loose  contact  finger  at  the  control- 
ler or  by  a  loose  cable  or  wire.     Remove  the  casing 
from  the    controller,    and    if   blisters  are  seen  on  the 
drum  of  the  controller  examine  the  finger  belonging  to 
this  particular  contact,  clean  it  and  screw  it  home  or 
bring  it  back  to  its  normal  form  should  it  have  been 
bent.     If  the  controller  looks  all  right  the  trouble  may 
be  found  to  be  due  to  a  loose  cable  connected  to  the 
terminals  of  a  motor.     Take  a  screwdriver  and  tighten 
all  cables  going  to  the  field  coils,  armature  and  brush 
holders.     Also  examine  the  brushes.     If  the   commu- 
tator looks  dark  and  burnt  it  may  be  due  to  a  brush 
which  has  worn  down  to  such  an  extent  that  the  brush 
springs  do  not  press  it  against  the  commutator.     In 
this  latter  case  substitute  a  new  brush,  but,  if  none  is 
at  hand,  cut  out  the  motor  and  go  ahead  with  the 
other. 

18.  The  car  starts  with  a  jerk,  but  afterward  runs 
smooth  and  normal.     There  is  a  short  circuit  probably 


HOW  TO  REMEDY  TROUBLES.         181 

in  the  rheostat.  Examine  the  rheostat  terminals  and 
remove  the  trouble,  which  may  be  due  to  the  crossing 
of  the  cables  or  a  loose  cable  touching  another  ter- 
minal. Should  the  trouble  be  internal,  namely,  inside 
of  the  rheostat,  do  not  touch  it  at  all,  but  run  your 
car  back  to  the  barns  and  report  the  defects. 

19.  A  motor  field  or  armature  coil  may  be  burnt 
out.     Cut  out  this  motor,  which  can  be  detected  by  the 
smell  of  shellac  and  burnt  cotton. 

20.  Should  the  speed  of  the  motor  increase  beyond 
normal,  a  field  magnet  coil  is  either  short-circuited  or 
burnt  out.     The  motor  should  be  cut  out. 

21.  Should  there  be  heavy  flashing  and  smoking 
in  the  controller,  it  is  due  to  dirt,  moisture,  metal  dust 
in  the  controller,  or  the  too  slow  turning  off  of  the 
controller.     Open  the  overhead  switch  and  blow  out 
the  dust  from  the  ring  terminals;  also  remove  all  dust 
at  the  lower  ends  of  the  controller  and  see  that  it  is 
dry. 

22.  Should  the  lamps  not  light  up  on  turning  the. 
lamp  switch,  see  if  the  lamp  circuit  fuse  is  not  blown. 
If  in  good  order  either  a  lamp  is  not  screwed  home 
into  its  socket  or  one  of  the  lamps  is  burnt  out.     If 
one  is  burnt  out  none  will  light  up,  because  they  are  in 
series. 

There  are  also  other  irregularities  which  may  occur 
which  it  is  well  for  the  motorman  to  understand,  al- 
though he  may  not  be  able  to  remedy  them. 

23.  One  motor  of  a  car  becomes  a  great  deal  hot- 
ter than  the  other.     This  may  be  due  to  uneven  distri- 
bution of  work  caused  by  difference  in  the  magnetic 
circuit  of  the  two  motors,  or  to  one  set  of  wheels  being 
smaller  in  diameter  than  the  other,  or  to  a  ground  in 


182  THE    MOTORMAN. 

the  field  coil  or  a  short  circuit  in  the  field  coil  of  the 
hot  motor. 

24.  Abnormal  heating  of  one  of  the  motor  arma- 
tures may  be  due  to  its  striking  the  field  poles  when 
rotating. 

25.  Heating  of  the  motor  may  also  be  due  to  a 
defective   brake,   caused   by  weak  release   springs  or 
too  short  a  brake  chain. 

26.  Heating  also  may  be  due  to  the  oil  or  grease 
used  which  does  not  melt  properly,  if  at  all.     A  full 
grease  or  oil  cup  is  no  sign  of  proper  lubrication.     If  it 
is  found  that  bearings  heat,  in  spite    of    full    grease 
cups,  take  a  clean  stick,  make  a  hole  through  the  grease 
down  to  the  shaft,  pour  in  soft  oil  and  go  ahead.     It 
may  be  well  occasionally  to  feel  the  car  axle  bearings, 
which  get  pretty  warm  when  insufficiently  supplied 
with  oil. 

27.  A  sharp  rattling  noise  when  the  car  is  trav- 
eling at  high  speed  is  the  consequence  of  an  uneven 
commutator.     A  commutator  that  is  flat  in  places,  or 
a  few  bars  that  have  become  loose  and  project  slightly, 
cause  the  brushes  to  be  quickly  forced  away  from  the 
commutator  by  the  high  bars,  and  to  be  forced  back 
onto  the  lower  ones  by  the  brush-holder  spring  as  soon 
as  a  high  bar  has  passed.     This  causes  heavy  sparking 
at  the  brushes  and  excessive  heating  of  the  commutator 
segments,    besides    the    rapid    wearing    down    of    the 
brushes.    The  rapid  succession  of  these  changes  causes 
the  noise,  and  this  can  be  remedied  only  in  the  repair 
shop.     It  should  be  reported. 

28.  A  dull  thumping  noise,  also  connected  with 
sparking  at  the  brushes,  may  be  due  to  the  armature 
striking  or  rubbing  against  the  pole  pieces.    If  this  is 
due  to  loose  bearings  the  cap  bolts.should  bo  tightened. 


HOW  TO  REMEDY  TROUBLES.         183 

but  if  on  account  of  worn-out  boxes  the  car  should  be 
taken  to  the  barn  at  a  slow  rate  of  speed,  and  reported 
without  delay. 

29.  If  the  car  starts  with  a  jerk  and  the  gears 
make  considerable  noise,  the  teeth  of  the  pinion  may  be 
worn,  fit  loosely  in  the  gear,  or  the  key  seat  on  the 
armature  shaft  may  have  been  made  wider  by  the  con- 
stant wear  of  a  loose  key.     This  trouble  should  be  re- 
ported as  soon  as  possible. 

30.  Loud  noise  from  the  gearing  is  sometimes  due 
to  loose  gears,  the  teeth  of  which  have  too  much  play. 
It  is  increased  if  the  gear  casing  is  partially  opened, 
caused  by  loose  bolts,  or  when  they  are  removed  en- 
tirely.      The   same   trouble   of  improper  meshing   of 
teeth  in  the  gears  may  be  due  to  a  bent  armature  shaft 
or  a  bent  car  axle.     The  trouble  should  be  reported  to 
the  car  inspector  or  other  proper  authority. 

31.  Another  noise  frequently  heard  is  the  thump- 
ing of  a  car  wheel  which  has  a  flat  spot.     The  trouble 
may  be  due  to  natural  wear,  or  due  to  poor  track, 
but  the  most  frequent  cause  is  the  improper  handling 
of  the  brake,  which  is  set  too  suddenly  and  prevents 
the  wheels  from  turning.  If  the  brake  is  set  too  tightly 
when  going  down  grade,  it  will  cause  the  wheels  to 
slide  along  the  rails  on  four  points,  which,  due  to  fric- 
tion, become  heated,  with  the  result  of  softening  that 
part  of  the  wheel,  which  will  wear  rapidly  into  a  flat 
place,  causing  a  disagreeable  hammering  noise  at  every 
revolution  of  the  wheel. 

32.  If  the  motors  start  with  a  jerk  or  do  not  run 
smoothly,  the  conductor  should  lift  one  of  the  trap 
doors  at  a  time,  while  the  car  is  running,  to  examine 
the  commutator  and  brushes  of  each  motor.     Should 
there  be  seen  a  flash  all  around  the  commutator  or 


184  THE    MOTORMAN. 

connecting  two  brushes,  then  there  is  an  open  circuit 
in  the  armature.  Cut  out  the  motor  and  proceed  on 
the  trip  with  the  other  motor  alone. 

Short  Circuits  and  Grounds.— A  short  circuit  on  a 
motor  in  a  car  means  that  by  some  cause  or  defect  a 
shorter  circuit  is  found  by  the  electric  current  other 
than  is  properly  provided  in  the  system,  and  it  has  the 
effect  of  weakening  or  disabling  the  part  thus  affected. 
For  instance,  assume  that  to  make  the  magnet  of  a 
motor  strong,  there  is  placed  around  it  500  turns  of 
wire ;  due  to  dampness  or  dirt,  let  there  be  cut  out  300 
or  400  turns ;  then  a  current  will  flow  through  but  100 
turns;  the  circuit  has  become  shorter  than  was  in- 
tended by  the  designer.  Such  defects  not  only  lead  to 
irregularity  in  handling,  but  cause  a  strain  on  the 
dynamo  in  the  power  station.  Every  second  that  a 
motor  runs  after  something  is  wrong  is  liable  greatly 
to  increase  the  damage.  Therefore,  cut  out  a  defective 
motor  the  moment  it  is  discovered.  Short  circuits  can 
be  caused  by  dirt  and  rain,  by  crossing  of  the  flexible 
wires  joined  to  the  motors  and  in  many  other  ways. 
A  short  circuit  on  a  line  means  that  nearly  all  or  all 
the  necessary  resistance  which  a  motor  or  other  trans- 
lating device  should  offer  when  in  good  condition  has 
been  removed  by  a  defect,  and  now  acts  as  a  conductor 
of  very  little  resistance  connecting  the  two  wires  con- 
stituting the  line.  In  a  railway  system  this  would 
mean  a  direct  connection  between  trolley  wire  and  rail, 
the  current  not  properly  passing  through  the  motors. 
A  grounded  motor,  or  a  short  circuit,  means  that 
some  part  of  the  insulation  has  become  defective  and 
that  the  current  has  found  its  wray  to  the  iron  core. 
In  most  railway  systems  used  at  present  the  trolley  wire 
is  one  of  the  conductors,  while  the  rails  form  the  ^ec- 


HOW  TO  REMEDY  TROUBLES.        185 

ond  or  return  conductor.  A  ground  on  a  motor  equip- 
ment indicates  that  a  part  of  the  field  or  the  armature 
winding,  through  which  the  current  should  flow  before 
reaching  the  car  wheel,  has  been  cut  out  of  action  by 
a  defect.  The  car  then  will  not  operate  so  well,  and, 
depending  on  the  seriousness  of  the  defect,  will  go 
slower  or  faster  than  when  in  good  order.  If  a  ground 
cuts  out  a  great  deal  of  the  motor  circuit  it  is  about 
equivalent  to  a  short  circuit.  If  a  guard  wire,  tele- 
graph or  telephone  wire  should  fall  over  the  trolley 
wire  and  touch  the  ground  it  would  establish  an  earth 
connection,  which  is  equivalent  to  a  short  circuit  on 
the  dynamo. 

Handling  Live  Wires. — Should  a  wire  be  found 
hanging  over  the  trolley  wire,  but  not  reaching  the 
ground,  it  should  be  removed  with  the  greatest  of  care. 
It  does  not  form  a  ground,  as  it  may  be  several  feet 
away  from  the  ground;  however,  it  is  charged  by 
touching  the  trolley  wire.  In  trying  to  remove  it  with 
the  bare  hands,  standing  on  the  ground,  the  man  who 
intends  to  give  his  services  to  remove  the  obstruction 
forms  himself  the  rest  of  the  circuit  and  establishes  a 
ground  through  his  body.  The  moment  he  touches  this 
apparently  lifeless  wire  with  his  bare  hands  the  cur- 
rent passes  through  his  body  into  the  ground. 

A  wire  covered  with  rubber  insulation  can  be 
handled,  but  even  in  this  case  the  same  precaution 
should  be  taken,  as  no  one  can  tell  how  good  the  in- 
sulation may  be.  Frequently  rubber  insulation  be- 
comes brittle  and  hard  when  exposed  to  atmospheric 
changes — hot  and  cold  weather,  rain  and  snow — and  in 
this  state  the  insulation  is  worse  than  none,  because 
persons  may  think  the  covering  still  to  be  an  insulator 
when,  in  fact,  it  may  be  carbonized  and  itself  a  partial 


186  THE    MOTORMAN. 

conductor.  In  damp  weather  and  with  high  voltages, 
as  now  commonly  used,  such  insulation  should  not  be 
relied  on  and  should  be  treated  as  if  the  wire  were  a 
bare  one. 

The  construction  man  on  his  tower  wagon  handles 
the  trolley  wire  with  bare  hands,  but  it  should  be  re- 
membered that  he  stands  on  a  high  wooden  ladder,  and 
therefore  is  well  insulated  from  the  ground.  Even 
in  his  lofty  position  he  has  to  be  on  his  guard,  because 
the  trolley  suspension  wires  in  some  cities  are 
connected  to  the  iron  poles  without  an  insulator  be- 
tween them,  only  one  insulator  being  provided,  which 
is  interposed  between  the  trolley  wire  and  the  span. 
If  he  touches  either  one  alone  he  is  safe,  but  if  he 
touches  the  trolley  wire  and  at  the  same  time  this 
span  wire  attached  to  the  iron  pole,  he  establishes 
a  connection  from  the  trolley  to  the  ground 
through  his  hands,  arms  and  body  and  has  to  suffer 
the  consequences.  In  most  towns  the  trolley  suspen- 
sion wires  are  now  insulated  at  both  ends,  so  that  they 
can  be  handled  without  danger. 

It  may  be  necessary  to  handle  a  live  trolley  wire 
which  has  broken  or  fallen  in  the  street,  or  a  tele- 
phone or  other  wire  which  has  fallen  across  the  trolley 
wire.  Never  take  hold  of  the  \vire  with  the  bare  hands. 
If  it  must  be  handled,  put  several  thicknesses  of  cloth- 
ing between  it  and  the  hands,  if  the  cloth  is  dry. 
Otherwise,  use  sticks  and  a  rope  to  remove  it. 


GLOSSARY. 


Ampere— The  standard  unit  of  electric  current  which 
is  equivalent  to  the  current  flowing  through  a  cir- 
cuit having  one  ohm  resistance  with  a  pressure  of 
one  volt. 

Volts 
Current^ — 

Resistance 

Armature— The  part  of  a  motor  or  dynamo  which  re- 
volves and  produces  power  or  generates  current. 

Arc— An  electric  current  flowing  across  the  air  gap 
or  space  between  the  points  of  contact. 

Brushes — On  railway  generators  and  motors  they  are 
blocks  of  carbon  held  in  brass  holders  with  light 
springs  to  press  them  against  the  commutator,  and 
through  which  the  current  passes  to  or  from  the 
commutator  and  armature,  or  from  the  stationary 
conductor  of  the  circuit  to  the  rotary  conductors 
or  vice  versa. 

Brush  Holders — Devices  to  hold  the  brushes;  they  are 
adjustable  so  that  the  brushes  can  be  lifted  to 
prevent  sparking. 

Bucking  Motor — A  motor  acting  in  opposition  through 
some  defect.  The  motor  must  be  located  and  cut 
out  of  circuit,  or  turn  off  switches  and  have  car 
conveyed  to  depot. 


188  THE    MOTORMAN. 

Catenary  Trolley — A  trolley  wire  which  is  supported 
by  hangers  from  a  steel  cable  running  just  above 
the  copper  wire  itself. 

Circuit-Breaker — An  automatic  switch  arranged  to 
open  whenever  the  current  becomes  greater  than 
a  certain  predetermined  amount.  It  consists  of 
a  few  turns  of  wire  around  an  iron  core, 
which  becomes  a  magnet  of  greater  and  greater 
power  as  the  current  increases  until  it  throws  open 
the  switch  or  releases  a  catch  which  allows  a  spring 
to  open  the  switch. 

Closed  Circuit— A  circuit  is  closed  when  its  conduct- 
ing parts  are  so  connected  as  to  allow  the  cur- 
rent to  flow. 

Commutator — A  set  of  copper  segments  separated  by 
thin  strips  of  mica  insulation  in  the  form  of  a 
drum;  through  the  segments  covered  by  the  posi- 
tive brushes  the  positive  current  passes  to  the 
armature  in  a  motor  and  from  it  in  a  dynamo. 

Compound  Winding — The  field  magnets  of  a  railway 
dynamo  always  have  two  windings,  through  one 
of  which,  the  "series,"  the  main  current  passes, 
and  through  the  other,  the  "shunt,"  a  branch  of 
the  main  current  passes. 

Conductors — The  part  of  the  dynamo,  motor  or  line, 
or  circuit  through  which  the  current  flows. 

Counter-Electro-Motive  Force — The  pressure  generated 
in  the  armature  of  the  motor  or  dynamo. 

Cut  Off  from  the  Line— Open  Circuit.  Car  disabled 
by  an  open  circuit. 

Diverter— A  rheostat  or  resistance  placed  in  circuit 
with  a  motor  to  reduce  the  current. 

Electro-Magnet — An  iron  or  steel  core  around  which 
a  spool  of  wire  is  placed  carrying  current. 


GLOSSARY.  189 

Electro-Motive  Force — The  voltage  or  volts'  pressure 
in  a  circuit ;  e.  g.,  the  trolley  circuit  has  au  electro- 
motive force  of  500  volts.  The  abbreviation  is 
e.  m.  f. 

Field — The  part  of  a  motor  or  dynamo  which  contains 
the  magnets. 

Fuse— A  strip  of  metal,  generally  some  alloy  of  lead, 
which  easily  melts  when  too  great  a  current  is 
flowing  in  the  circuit.  It  is  mounted  usually  on  a 
piece  of  porcelain  called  a  fuse  block. 

Generator — Has  the  same  meaning  as  dynamo,  but  is 
commonly  used  to  denote  the  large  machines  in 
the  station. 

Grounded  Circuit — A  circuit  in  which  the  ground 
forms  part  of  the  conducting  path. 

Horsepower — The  standard  rate  of  work  being  33,000 
foot-pounds  per  minute.  If  a  machine  can  lift 
1,000  pounds  33  feet  in  one  minute  its  capacity  is 
one  horsepower.  The  abbreviation  is  hp.  Elec- 
trical equivalent,  1  hp.=746  watts. 

Insulation— A  non-conductor,  as  air,  rubber,  mica,  var- 
nish, etc.,  through  which  electricity  does  not 
readily  pass. 

Interlocking  Device — A  part  of  the  controller  which 
prohibits  the  motorman  from  reversing  while  the 
current  is  on. 

Lightning  Arresters — They  are  devices  which  offer  a 
by-pass  to  lightning  to  prevent  damage  to  ma- 
chines when  the  line  is  carrying  a  discharge  of 
lightning  by  conducting  it  to  the  earth. 

Magnetic  Blow-Out—When  switches  are  opened  or  cur- 
rent shut  off  in  controllers,  an  arc  is  formed  which 
is  current  passing  through  the  air  from  one  con- 
ductor to  the  other.  A  magnet  is  placed  near  the 


190  THE    MOTORMAN. 

point  where  the  arc  is  formed  and  draws  it  aside 
and  blows  it  out. 

Ohm — The  standard  of  electrical  resistance  through 
which  one  ampere  of  current  will  flow  with  a  pres- 
sure of  one  volt.  Ohms  =  Volts  -v-  Current. 

Open  Circuit— A  circuit  is  open  when  its  conducting 
parts  are  disconnected  in  such  a  manner  as  to 
prevent  the  current  from  flowing. 

Parallel  or  Multiple  Connection — A  circuit  in  which  the 
current  divides  and  part  passes  through  each  mo- 
tor, dynamo  or  other  electrical  device. 

Poles  or  Pole  Pieces— The  core  ends  which  project  on 
the  fields  and  conform  to  the  shape  of  the  arma- 
ture, and  generally  carry  the  field  windings. 

Resistance— An  obstruction  to  the  flow  of  current.  All 
substances  have  some  resistance,  but  resistance 
boxes  or  rheostats  have  iron  wire  or  sometimes 
carbon  strips  for  the  circuit.  Resistance  produces 
heat  in  the  circuit,  and  by  this  means  the  current 
in  passing  through  an  electric  car  heater  makes 
the  wires  very  hot. 

Reversing  Cylinder— The  part  of  the  controller  which 
controls  the  direction  of  motion  of  the  motors. 

Rotary  Converter — A  type  of  electrical  machine  for 
changing  direct  to  alternating  current,  or  vice 
versa. 

Safety  Stop — An  attachment  which  prevents  the  con- 
troller cylinder  from  being  turned  past  a  certain 
running  position  when  a  motor  is  cut  out. 

Series  Connection  — When  the  current  passes  through 
one  motor,  dynamo  or  electrical  device  and  there- 
after into  one  or  more  devices. 

Short  Circuit— A  short  cut  made  by  the  current  to 
a  path  outside  of  the  regular  circuit. 


GLOSSARY.  191 

Sparking — The  flashing  of  the  current  which  occurs  at 
the  commutator  when  there  is  poor  contact,  the 
brushes  are  in  bad  order,  the  commutator  is  dirty, 
or  the  dynamo  or  motor  is  carrying  too  heavy  a 
load. 

Transformer— A  combination  of  coils  of  wire  about 
an  iron  core  by  means  of  which  alternating  cur- 
rent can  be  changed  in  pressure. 

Volt — The  standard  of  electrical  pressure,  or  the  pres- 
sure to  force  one  ampere  of  current  through  one 
ohm  resistance.  Volts  =  Amperes  X  Ohms. 

Watt— The  rate  of  performance  of  work  measured 
electrically ;  the  capacity  of  a  dynamo  or  motor  is 
measured  in  watts  and  is  the  product  of  volts  by 
amperes.  A  kilowatt  is  1,000  watts  and  is  equal  to 
1.34  hp. 


INDEX. 


Acceleration,  Automatic  126 

Accidents,  Precautions  Against 135 

Air  Brakes,  Automatic 165 

—Operation  of 166,  168 

— Emergency  Feature 163 

— Motorman's  Valve  156 

— Parts  of 151 

— Operation  of   158 

— Storage    171 

—Straight 151 

Air  Compressor  155 

—Circuits   88 

— Governor  155 

Air  and  Hand  Brake  Rigging 157 

Alternating-Current  Feeding  System 35 

Alternating-Current-Direct-Current  Feeding  System  35 

Armature  11,  53 

—Core 54 

Boilers  25 

—Fire-Tube  25 

—Water-Tube  27 

Brake  Leverage  145 

—Electric  146 

—Hand  141 

—Kinds  of 141 

—Magnetic  148 

—Rigging  143 

Brakeshoe 140 

Brush  Holder  . .  .58 


INDEX.  193 

Car  Wiring 87 

—Chicago  City  Railway 89 

Cars  4 

—City 9 

—Hints  on  Handling 172 

— Interurban    9 

Catenary  Construction   48 

Choke  Coil   87 

Circuit-Breaker   80 

Commutator  18,  53 

Conductor's  Valve 167 

Control  Battery 127 

— Electro-Pneumatic    122 

— Series-Parallel  93,  98 

— Type-M  117 

— Type-M  Circuits   121 

—Unit  Switch  122 

—Varying  Field   92 

Controller,  Type-K-28  113 

—Master  118 

— Type-B    Ill 

— Type-K 101 

— Type-L 110 

—With  Contactors 112 

Controllers   99 

— Operation  of 129 

— Reversing  Cylinder  103 

Conduit  System 44 

Contactors  118 

Direct-Current  Feeding  System 33 

Distribution,  Methods  of 31 

Dynamo  17 

—Edison   20 

— Multipolar 21 

— Principle  of  16 

Electricity,  Units  for  Measuring 30 

Engines,  Steam 27 

Feeding  130 

Fuses  . .  .81 


194  THE    MOTORMAN. 

Gear  Case 63 

Gears 60 

Heater  Circuits 88 

Insulation   39 

Insulators   40 

—High-Tension   51 

Lighting  Circuits 90 

Lightning  Arrester  83 

Locomotives   46 

Magnetic  Lines  of  Force 12 

—Needle  15 

—Poles  13 

Magnets  10 

— Electro  14 

—Field  19 

Motor,  Parts  of 56 

—Principle  of 15 

— Cars  4 

—Circuits  96 

— Connections  on  Successive  Points 103 

— Interpole  68 

— Reversing  in  Emergency 131 

— Single-Phase  : .  70 

— Suspension  65 

Operation  Around  Curves 135 

—Failure  of  Car  to  Start 177 

Parallel  Connection 97 

Power,  Hints  on  Saving 132 

— Lost,  Chart  Showing 133 

— Station  24 

Pressure    30 

Push-Button  Circuits 90 

Repairs 137 

Resistance    30,  94 

Reverser   123 


INDEX.  195 

Rheostat   94 

Right  of  Way 3 

Rotary  Converter  37 

Series  Connection  96 

Short-Circuits  184 

Storage-Battery  Cars  45 

Switchboard    30 

Switches,  Main   79 

Third-Rail  Shoes  76 

—System    42 

Track  3 

Trailers   4 

Transformer,  Principle  of 33 

Transmission  Lines 50 

Trolley  Base 74 

— Fittings    40 

— Pantagraph   76 

—Wire  47 

Trucks 6 

— Maximum  Traction  7 

Turbines,  Steam  28 

Wheels,  Flat 173 

Wires,  Live  ...  .185 


